各种模板（待补全）

昨天DQS来给我们开班会辣，DQS曰：“板子很重要！”。所以就来搞板子…
听说板子要加图？

SPFA（1557热浪）

#include<cstdio>#include<queue>using namespace std;const int maxn=50000;struct Edge{    int ff;    int to;    int d;    int next;}edge[maxn];int head[maxn];bool vis[maxn];int dist[maxn];int tot;void add(int fff,int tt,int d){    edge[++tot].ff=fff;    edge[tot].to=tt;    edge[tot].d=d;    edge[tot].next=head[fff];    head[fff]=tot;}queue<int >q;void spfa(int s){    dist[s]=0;    q.push(s);    while(!q.empty())    {        int x=q.front();        vis[x]=0;        q.pop();        for(int i=head[x];i;i=edge[i].next)        {            Edge e=edge[i];            if(dist[e.to]>dist[x]+e.d)            {                dist[e.to]=dist[x]+e.d;                if(!vis[e.to])                {                    q.push(e.to);                    vis[e.to]=1;                }            }        }    }}int main(){    int n,m,st,se;    scanf("%d%d%d%d",&n,&m,&st,&se);    for(int i=1;i<=n;i++)    dist[i]=0x7fffffff;    for(int i=1;i<=m;i++)    {        int a,b,c;        scanf("%d%d%d",&a,&b,&c);        add(a,b,c);        add(b,a,c);    }    spfa(st);    printf("%d",dist[se]);    return 0;}

dijsktra（热浪

#include<cstdio>#include<queue>#include<cstring>using namespace std;const int maxn=100000*2;const int maxm=1500;const int inf=0x7fffffff;struct heap{    int p;    int dis;    bool operator < (const heap &hah)const    {        return dis > hah.dis;    } };int n,m,st,se;priority_queue<heap>q;struct Edge{    int to;    int d;    int next;}edge[maxn];bool vis[maxn];int head[maxn];int dist[maxn];int tot;void add(int f,int t,int d){    edge[++tot].to=t;    edge[tot].d=d;    edge[tot].next=head[f];    head[f]=tot;} bool flag=false;void DJ() {    for(int i=1;i<=n;i++)        dist[i]=0x7fffffff;    memset(vis,0,sizeof(vis));    q.push((heap){st,0});    int cnt=0;    while(!q.empty())    {        heap p=q.top();        q.pop();        if(p.p==se)        {            printf("%d",p.dis);            return;        }        if(vis[p.p])            continue;        vis[p.p] = true;        for(int i=head[p.p];i;i=edge[i].next)        {            Edge e=i[edge];            int v=edge[i].to;            if(dist[v]>dist[p.p]+e.d)            {                dist[v]=dist[p.p]+e.d;                q.push((heap){v,p.dis+edge[i].d});            }        }    }}int main(){    scanf("%d%d%d%d",&n,&m,&st,&se);    for(int i=1;i<=m;i++)    {        int a,b;        int c;        scanf("%d%d%d",&a,&b,&c);        add(a,b,c);        add(b,a,c);    }    DJ();    return 0;}

kruskal（裸

#include<cstdio>#include<cstring>#include<algorithm>#include<queue>#include<stack>#include<iostream>using namespace std;const int maxm=200000+500;const int inf=0x7fffffff;int n,m;struct meico{    int f;    int to;    int d;}sz[maxm];int head[maxm],dist[maxm];int tott;void add2(int f,int t,int d){    sz[++tott].f=f;    sz[tott].to=t;    sz[tott].d=d;}int fa[maxm];int find(int x){    return x==fa[x]?x:fa[x]=find(fa[x]);}void kclr(){    for(int i=1;i<=n;i++)        fa[i]=i;}bool cmp(meico a,meico b){    return a.d<b.d;}void K(){    kclr();    int ans=0;    sort(sz+1,sz+tott+1,cmp);    for(int i=1;i<=tott;i++)    {        int ff=find(sz[i].f);        int tt=find(sz[i].to);        if(ff!=tt)        {            fa[ff]=tt;            ans+=sz[i].d;        }    }    printf("%d\n",ans);}void read(int &a){    a=0;    char c=getchar();    while(c<'0'||c>'9')    {        c=getchar();    }    int ans=0;    while(c<='9'&&c>='0')    {        ans=(ans<<1)+(ans<<3);        ans+=c-'0';        c=getchar();    }    a=ans;    return;} int main(){    read(n),read(m);    for(int i=1;i<=m;i++)    {        int a,b,c;        read(a),read(b),read(c);        add2(a,b,c);        add2(b,a,c);    }    K();        return 0;}

倍增LCA（小机房的树

#include<algorithm>#include<cstdio> using namespace std;const int maxn=150050;int n,m;int fa[maxn][30]; int dist[maxn];int deep[maxn];struct Edge{    int to;    int d;    int next;}edge[maxn];int head[maxn];int tot;void add(int f,int t,int d){    ++tot,tot[edge]=(Edge){t,d,f[head]};    f[head]=tot; }void dfs(int t,int f,int dep,int dis){    0[t[fa]]=f,t[deep]=dep,dist[t]=dist[f]+dis;    for(int i=t[head];i;i=edge[i].next)    {        Edge e=i[edge];        if(e.to[deep])            continue;        dfs(e.to,t,dep+1,e.d);    }}int ii;void clr(){    for(ii=1;(1<<ii)<=n;ii++);//ii = log2(n) + 1;    for(int j=1;j<=ii;j++)    for(int i=0;i<n;i++)        fa[i][j]=fa[fa[i][j-1]][j-1];}int lca(int x,int y){    int a=x,b=y;    int ans=0;    if(deep[x]<deep[y])        swap(x,y);    for(int j=ii;j>=0;j--)        if(deep[fa[x][j]]>=deep[y])            x=fa[x][j];    if(x==y)        return dist[a]+dist[b]-(dist[x]<<1);    for(int j=ii;j>=0;j--)        if(fa[x][j]!=fa[y][j])            x=fa[x][j],y=fa[y][j];    x=fa[x][0];    return dist[a]+dist[b]-(dist[x]<<1);}int main(){    scanf("%d",&n);    for(int i=1;i<n;i++)    {        int a,b,c;        scanf("%d%d%d",&a,&b,&c);        add(a,b,c),add(b,a,c);    }    dfs(0,50005,1,0);    clr();    int q;    scanf("%d",&q);    while(q--)    {        int a,b;        scanf("%d %d",&a,&b);        printf("%d\n",lca(a,b));    }    return 0;}

tarjan求SCC(信息传递

#include<cstdio>#include<stack>#include<iostream>using namespace std;const int maxn=500000+10;int head[maxn];int scc[maxn];int pre[maxn];int low[maxn];struct Edge{    int f;    int to;    int next;}edge[maxn];int tot;void add(int fff,int ttt){    edge[++tot].f=fff;    edge[tot].to=ttt;    edge[tot].next=head[fff];    head[fff]=tot;}stack<int> s;int ans=0x7fffffff;int scccnt;int dfs_clock;void dfs(int u){    pre[u]=low[u]=++dfs_clock;    s.push(u);    for(int i=head[u];i;i=edge[i].next)    {        Edge e=edge[i];        if(!pre[e.to])        {            dfs(e.to);            low[u]=min(low[u],low[e.to]);        }        if(!scc[e.to])        {            low[u]=min(low[u],pre[e.to]);        }    }    if(pre[u]==low[u])    {        int sccsz=0;        scccnt++;        while(1)        {            int x=s.top();            scc[x]=scccnt;            s.pop();            sccsz++;            if(x==u)            {                if(sccsz!=1)                ans=min(ans,sccsz);                break;            }               }    }}int main(){    int n;    scanf("%d",&n);    for(int i=1;i<=n;i++)    {        int x;        scanf("%d",&x);        add(i,x);    }    for(int i=1;i<=n;i++)    {        if(!pre[i])        dfs(i);    }    printf("%d",ans);    return 0;}

tarjan缩点（爱在心中

#include<cstdio>#include<stack>#include<algorithm>using namespace std;const int maxn=100000+500;const int maxm=400000+500;int n,m;int ff[maxn],tt[maxn];struct Edge{    int f;    int to;    int next;}edge[maxm];int tot;int head[maxn]; void add(int f,int t){    edge[++tot].f=f;    edge[tot].to=t;    edge[tot].next=head[f];    head[f]=tot;}int pre[maxn],low[maxn];int scc[maxn];int cd[maxn],rd[maxn];int dfs_cnt;stack<int>s;int scnt;int hcnt;bool bigscc[maxn];void dfs(int x){    pre[x]=low[x]=++dfs_cnt;    s.push(x);    for(int i=head[x];i;i=edge[i].next)    {        int v=edge[i].to;        if(!pre[v])        {            dfs(v);            low[x]=min(low[x],low[v]);        }        if(!scc[v])        {            low[x]=min(low[x],pre[v]);        }    }    if(pre[x]==low[x])    {        int nn=0;        scnt++;        while(1)        {            nn++;            int hah=s.top();            scc[hah]=scnt;            s.pop();            if(hah==x)            {                if(nn>=2)                {                    bigscc[scnt]=1;                    hcnt++;                }                break;            }        }    }}int sccn;bool pd(){    int cdcnt=0;    for(int i=1;i<=scnt;i++)    {        if(cd[i]==0)        {            cdcnt++;            sccn=i;        }    }    if(cdcnt==1&&bigscc[sccn])    return true;    else    return false;}int main(){    scanf("%d%d",&n,&m);    for(int i=1;i<=m;i++)    {        scanf("%d%d",&ff[i],&tt[i]);        add(ff[i],tt[i]);    }    for(int i=1;i<=n;i++)    {        if(!pre[i])        dfs(i);    }    printf("%d\n",hcnt);    for(int i=1;i<=m;i++)    {        if(scc[ff[i]]!=scc[tt[i]])        {            cd[scc[ff[i]]]++;            rd[scc[tt[i]]]++;        }    }    if(!pd())    {        puts("-1");        return 0;    }    for(int i=1;i<=n;i++)    {        if(scc[i]==sccn)        printf("%d ",i);    }    return 0;}

ST表（POJ3264

#include<algorithm>#include<cstdio>#include<cmath>using namespace std;const int maxn=50000+500;int num[maxn];int st[maxn][30];int st1[maxn][30];int n;void ST(){    for(int i=1;i<=n;i++)        st[i][0]=st1[i][0]=num[i];    int k=(log(n)/log(2));    for(int j=1;j<=k;j++)    {        for(int i=1;i<=n;i++)        {            if(i+(1<<(j-1))<=n)            {                st[i][j]=max(st[i][j-1],st[i+(1<<(j-1))][j-1]);                st1[i][j]=min(st1[i][j-1],st1[i+(1<<(j-1))][j-1]);            }        }    }}int ask_max(int x,int y){    int k=log(y-x+1)/log(2);    return max(st[x][k],st[y-(1<<k)+1][k]);}int ask_min(int x,int y){    int k=log(y-x+1)/log(2);    return min(st1[x][k],st1[y-(1<<k)+1][k]);}int main(){    int q;    scanf("%d%d",&n,&q);    for(int i=1;i<=n;i++)        scanf("%d",&num[i]);    ST();     while(q--)    {        int a,b;        scanf("%d%d",&a,&b);        printf("%d\n",ask_max(a,b)-ask_min(a,b));     }    return 0;}

线段树(CODEVS 线段树练习3

#include<cstdio>using namespace std;const int maxn=2500000;typedef long long ll;struct tree{    ll l;    ll r;    ll sum;    ll add;}t[maxn<<2];ll num[maxn];void up(ll p){    t[p].sum=(t[p<<1].sum+t[p<<1|1].sum);}void buff(ll p){    if(t[p].add)    {        t[p<<1].sum+=t[p].add*(t[p<<1].r-t[p<<1].l+1);        t[p<<1|1].sum+=t[p].add*(t[p<<1|1].r-t[p<<1|1].l+1);        t[p<<1].add+=t[p].add;        t[p<<1|1].add+=t[p].add;        t[p].add=0;    }    up(p);}void expand(ll l,ll r,ll p){    t[p].r=r;    t[p].l=l;    if(r==l)    {        t[p].sum=num[l];        return;    }    ll mid=(l+r)>>1;    expand(l,mid,p<<1);    expand(mid+1,r,p<<1|1);    up(p);}void addd(ll l,ll r,ll p,ll v){    if(l<=t[p].l&&t[p].r<=r)    {        t[p].sum+=(t[p].r-t[p].l+1)*v;        t[p].add+=v;        return;    }    buff(p);    up(p);    ll mid=(t[p].l+t[p].r)>>1;    if(l<=mid)        addd(l,r,p<<1,v);    if(mid+1<=r)        addd(l,r,p<<1|1,v);    buff(p);    up(p);}ll ask(ll l,ll r,ll p){    ll ans=0;    if(l<=t[p].l&&t[p].r<=r)    {        return t[p].sum;    }    buff(p);    up(p);    ll mid=(t[p].l+t[p].r)>>1;    if(l<=mid)        ans+=ask(l,r,p<<1);    if(mid+1<=r)        ans+=ask(l,r,p<<1|1);    return ans;}int main(){    ll n,q;    scanf("%lld",&n);    scanf("%lld",&q);    expand(1,n,1);    while(q--)    {        ll hah;        scanf("%lld",&hah);        if(hah==1)        {            ll a,b;            ll c;            scanf("%lld%lld%lld",&a,&b,&c);            addd(a,b,1,c);        }        else        {            ll a,b;            scanf("%lld%lld",&a,&b);            printf("%lld",ask(a,b,1));        }    }    return 0;}

//禁奥义·树链剖分（边）
/*

#include<algorithm>#include<iostream>#include<cstring> #include<string>#include<cstdio>#define mem(a) memset(a,0,sizeof(a))using namespace std;const int maxn=100000+500;struct Edge{    int to;    int d;    int next;}edge[maxn];int tot;int n;int head[maxn];int add(int f,int t,int d){    edge[++tot]=(Edge){t,d,head[f]};    head[f]=tot;}int ff[maxn],tt[maxn],dd[maxn];int siz[maxn],deep[maxn],top[maxn];int fa[maxn],son[maxn];void dfs1(int f,int t){    deep[t]=deep[f]+1;    fa[t]=f;    siz[t]=1;     for(int i=head[t];i;i=edge[i].next)    {        Edge e=edge[i];        if(e.to==f)        continue;        dfs1(t,e.to);        siz[t]+=siz[e.to];        if(siz[e.to]>siz[son[t]]||!son[t])            son[t]=e.to;    }}int xdstot;int xdsb[maxn];void dfs2(int u,int topu){    top[u]=topu;    xdsb[u]=++xdstot;    if(!son[u])        return;    dfs2(son[u],topu);    for(int i=head[u];i;i=edge[i].next)    {        Edge e=edge[i];        if(e.to==fa[u]||e.to==son[u])            continue;        dfs2(e.to,e.to);    }}struct Tree{    int l,r;    int maxx,sum;}t[maxn*4];void up(int p){    t[p].maxx=max(t[p<<1].maxx,t[p<<1|1].maxx);}void expand(int p,int l,int r){    t[p].l=l;    t[p].r=r;    if(l==r)    {        t[p].maxx=0;        return;    }    int mid=(l+r)>>1;    expand(p<<1,l,mid);    expand(p<<1|1,mid+1,r);    up(p);}void change(int p,int pos,int v){    if(t[p].l==t[p].r)    {        t[p].maxx=v;        return;    }    int mid=(t[p].l+t[p].r)>>1;     if(pos<=mid)        change(p<<1,pos,v);    else        change(p<<1|1,pos,v);    up(p);}int ask_max(int p,int l,int r){    if(l<=t[p].l&&t[p].r<=r)    {        return t[p].maxx;    }    int mid=(t[p].l+t[p].r)>>1;    int ans=0;    if(l<=mid)        ans=max(ans,ask_max(p<<1,l,r));    if(mid+1<=r)        ans=max(ans,ask_max(p<<1|1,l,r));    return ans;}int find(int x,int y){    int fax=top[x];    int fay=top[y];    int ans=0;    while(fax!=fay)    {        if(deep[fax]<deep[fay])        {            swap(fax,fay);            swap(x,y);        }        ans=max(ans,ask_max(1,xdsb[fax],xdsb[x]));        x=fa[fax];        fax=top[x];    }    if(deep[x] > deep[y])        swap(x,y);    if(x!=y)    {        if(deep[x]>deep[y])        swap(x,y);        ans=max(ans,ask_max(1,xdsb[x]+1,xdsb[y]));    }    return ans;}void clr(){    memset(edge,0,sizeof(edge));    memset(ff,0,sizeof(ff));    memset(tt,0,sizeof(tt));    memset(dd,0,sizeof(dd));    memset(t,0,sizeof(t));    memset(head,0,sizeof(head));    memset(son,0,sizeof(son));    memset(top,0,sizeof(top));    memset(deep,0,sizeof(deep));    memset(siz,0,sizeof(siz));    memset(fa,0,sizeof(fa));    memset(xdsb,0,sizeof(xdsb));    tot=0;    xdstot=0;}int main(){    int t;    scanf("%d",&t);    while(t--)    {        clr();        scanf("%d",&n);        for(int i=1;i<n;i++)        {            scanf("%d%d%d",&ff[i],&tt[i],&dd[i]);            add(ff[i],tt[i],dd[i]);            add(tt[i],ff[i],dd[i]);                 }        dfs1(20000,1);        dfs2(1,1);        expand(1,1,n);        for(int i=1;i<n;i++)        {            if(deep[ff[i]]>deep[tt[i]])                swap(ff[i],tt[i]);            change(1,xdsb[tt[i]],dd[i]);         }        char hah[233];        while(1)        {            scanf("%s",hah);            if(hah[0]=='D')                break;            else            {                int a,b;                scanf("%d%d",&a,&b);                if(hah[0]=='Q')                    printf("%d\n",find(a,b));                else                    change(1,xdsb[tt[a]],b);            }        }    }    return 0;}

*/

二分（跳石头

#include<cstdio>using namespace std;const int maxn=100000+50; int num[maxn];int L,n,m;int ans;bool hah(int x){    int cnt=0;    for(int i=0;i<=n;)    {        int t = num[i];        i ++;        while((num[i]-t)<x && i <= n)         {            cnt ++;            i ++;        }    }    if(cnt<=m)//        return true;    else        return false;}int ef(){    int l=1,r=L;    while(l<=r)    {        int mid=(l+r)>>1;        if(hah(mid))        {            l=mid + 1;        }        else        {            r=mid - 1;        }    }    return r;}int main(){    scanf("%d%d%d",&L,&n,&m);    for(int i=1;i<=n;i++)        scanf("%d",&num[i]);    num[++n]=L;    printf("%d",ef());    return 0;}

01+完全+多重背包

#include<cstdio>#include<algorithm> using namespace std;const int maxn=300000+500;int v[maxn];int w[maxn];int m[maxn];int dp[maxn];int n,V;void ly(int vv,int ww){    for(int j=V;j>=vv;j--)        dp[j]=max(dp[j-vv]+ww,dp[j]);}void wq(int vv,int ww){    for(int j=vv;j<=V;j++)        dp[j]=max(dp[j-vv]+ww,dp[j]);}inline void dc(int i){    if(m[i]*v[i]>=V)    {        wq(v[i],w[i]);        return;    }    else    {        int k=1;        while(k<m[i])        {            ly(k*v[i],k*w[i]);            m[i]-=k;            k<<=1;        }        ly(m[i]*v[i],m[i]*w[i]);    }}int main(){    scanf("%d%d",&n,&V);    for(int i=1;i<=n;i++)        scanf("%d%d%d",&v[i],&w[i],&m[i]);    for(int i=1;i<=n;i++)    {        if(m[i]==1)            ly(v[i],w[i]);        else if(m[i]==-1)            wq(v[i],w[i]);        else            dc(i);    }    int ans=0;    for(int i=0;i<=V;i++)    ans=max(ans,dp[i]);    printf("%d",ans);    return 0;}

模大质数情况下的逆元

#include<cstdio>#include<iostream>using namespace std;typedef long long ll;const int ha=10000007; int ksm(int x,int y){    if(y==1) return x%ha;    if(y==0) return 1;    int hah=ksm(x,y/2)%ha;    if(y%2==0)    return ((hah%ha)*(hah%ha))%ha;    else    return (((hah%ha)*(hah%ha)%ha)*(x%ha))%ha;}int inverse(int b){    return ksm(b,ha-2)%ha;} int main(){    int n,m;    cin>>n>>m;    int ans=inverse(m)%ha;    cout<<n/m<<endl;    cout<<n*ans;    return 0;}

对拍器

#include<bits/stdc++.h>using namespace std;int main(){    int tot=1;    while(1)    {        printf("Case:%d",tot++);        system("data.exe");        system("std.exe");        system("baoli.exe");        if(!system("fc std.txt baoli.txt"))            puts("AC");        else            system("pause");    }    return 0;}

map（dcOJ expedition

#include<cstdio>#include<map>using namespace std;typedef unsigned long long ll;ll n;map<ll,ll>mm;map<ll,ll>::iterator it;void read(ll &a){    char c=getchar();    ll flag=1;    while(c<'0'||c>'9')    {        if(c=='-')            flag=-1;        c=getchar();    }    ll ans=0;    while(c<='9'&&c>='0')        ans=ans*10+c-'0',c=getchar();    a=ans*flag;    return;}int main() {    freopen("expedition.in","r",stdin);    freopen("expedition.out","w",stdout);    read(n);    for(ll i=1;i<=n;i++)    {        ll a,b;        read(a),read(b);        mm[b]+=a;    }    it=mm.begin();    ll ans=0;    for(;it!=mm.end();it++)    {        ll hah=it->second;         ans+=hah*hah;    }    printf("%llu",ans);    fclose(stdin);    fclose(stdout);    return 0;}

exgcd（CODEVS 解的个数

#include<cstdio>using namespace std;typedef long long ll;ll exgcd(ll a,ll b,ll &x,ll &y){    if(b==0)    {        x=1,y=0;        return a;    }    ll r=exgcd(b,a%b,x,y);    ll t=x;    x=y;    y=t-(a/b)*y;    return r;}int main(){    int tott=0;    int n;    scanf("%d",&n);    while(n--)    {        ll a,b,c,p,q,r,s;        ll x,y;        scanf("%lld%lld%lld%lld%lld%lld%lld",&a,&b,&c,&p,&q,&r,&s);        if(q<p||s<r)        {            puts("0");            continue;        }        if(a==b&&a==0)        {            if(c==0)                printf("%lld\n",(q-p+1)*(s-r+1));            else                puts("0");            continue;        }        c*=-1;        ll hah=exgcd(a,b,x,y);        if(c%hah)        {            puts("0");            continue;         }         int tot=0;        if(b==0)        {            while(y>=r)                y-=a;            while(y<=s)            {                y+=a;                if((y*b==c)&&(r<=y&&y<=s))                    tot++;            }            printf("%d\n",tot);        }        else        {            a/=hah,b/=hah,c/=hah;            x*=c,y*=c;            while(x>=p)                x-=b,y+=a;            while(x<=q)            {                x+=b,y-=a;                if((p<=x&&x<=q)&&(r<=y&&y<=s))                    tot++;            }            printf("%d\n",tot);        }    }    return 0;}

埃氏筛法

#include<cstdio>using namespace std;const int maxn=1000000;bool sus[maxn];int ss[maxn];int cnt=0;int n;int main(){    scanf("%d",&n);    for(int i=2;i<=n;i++)    {        if(!sus[i])        {            ss[++cnt]=i;            int x=i;            int t=2;            while(x*t<=maxn)            {                sus[x*t]=1;                t++;            }        }        else            continue;    }    for(int i=1;i<=cnt;i++)        printf("%d\n",ss[i]);}

快速幂（递归

#include<algorithm>#include<cstdio>using namespace std;typedef long long ll; const ll ha=1e9+7;ll ksm(ll x,ll y){    if(y==0)    return 1;    if(y==1)    return x%ha;    ll hah=ksm(x,y>>1);    if(y&1)     return (((hah%ha)*(hah%ha))%ha*(x%ha));    return ((hah%ha)*(hah%ha))%ha;}ll n,m;int main(){    scanf("%lld%lld",&n,&m);    printf("%lld",ksm(n,m));        }

子集枚举

#include<bits/stdc++.h>using namespace std;const int maxn=50; bool vis[maxn];int n;void dfs(int tmp,int cnt){    if(cnt>n)    {        for(int i=1;i<=n;i++)        {            if(!i[vis])            printf("%d ",i);        }        puts("");        return;    }    for(int i=tmp;i<=n;i++)    {        if(!i[vis])        {            i[vis]=1;            dfs(i+1,cnt+1);            i[vis]=0;            dfs(i+1,cnt+1);        }    }}int main(){    scanf("%d",&n);    dfs(1,1);}