[Contest] IOI2011 day1 题目汇总

跟着ZZY神犇刷ioi题

garden

不会做，只会做倍增69分

以后再填坑

#include<cstdio>#include<cstdlib>#include<algorithm>using namespace std;inline char nc(){static char buf[100000],*p1=buf,*p2=buf;if (p1==p2) { p2=(p1=buf)+fread(buf,1,100000,stdin); if (p1==p2) return EOF; }return *p1++;}inline void read(int &x){char c=nc(),b=1;for (;!(c>='0' && c<='9');c=nc()) if (c=='-') b=-1;for (x=0;c>='0' && c<='9';x=x*10+c-'0',c=nc()); x*=b;}int N,M,P,Q;int G[2005];int R[150005][2];int size[150005];int f1[150005],f2[150005];int F1[150005][35],F2[150005][35];int Enf1[150005][35],Enf2[150005][35];int tot;inline int Query(int s,int K){int flag=0;for (int k=30;k>=0;k--)if (K&(1<<k)){if (!flag || size[s]==1)flag=Enf1[s][k],s=F1[s][k];elseflag=Enf2[s][k],s=F2[s][k];}return s;}int main(){freopen("t.in","r",stdin);freopen("t.out","w",stdout);read(N); read(M); read(P); P++;for (int i=1;i<=M;i++)read(R[i][0]),read(R[i][1]),R[i][0]++,R[i][1]++;for (int i=1;i<=M;i++){int u=R[i][0],v=R[i][1];size[u]++; size[v]++;if (!f1[u]) f1[u]=v; else if (!f2[u]) f2[u]=v;if (!f1[v]) f1[v]=u; else if (!f2[v]) f2[v]=u;}for (int i=1;i<=N;i++){F1[i][0]=f1[i]; if (f1[f1[i]]==i) Enf1[i][0]=1;F2[i][0]=f2[i]; if (f1[f2[i]]==i) Enf2[i][0]=1;}for (int k=1;k<=30;k++)for (int i=1;i<=N;i++){if (Enf1[i][k-1] && size[F1[i][k-1]]!=1){F1[i][k]=F2[F1[i][k-1]][k-1];Enf1[i][k]=Enf2[F1[i][k-1]][k-1];}else{F1[i][k]=F1[F1[i][k-1]][k-1];Enf1[i][k]=Enf1[F1[i][k-1]][k-1];}if (Enf2[i][k-1] && size[F2[i][k-1]]!=1){F2[i][k]=F2[F2[i][k-1]][k-1];Enf2[i][k]=Enf2[F2[i][k-1]][k-1];}else{F2[i][k]=F1[F2[i][k-1]][k-1];Enf2[i][k]=Enf1[F2[i][k-1]][k-1];}}read(Q);for (int i=1;i<=Q;i++)read(G[i]);for (int i=1;i<=Q;i++){int ans=0;for (int j=1;j<=N;j++)if (Query(j,G[i])==P)ans++;printf("%d\n",ans);}return 0;}

ricehub

单调的维护一下中位数和sum

#include<cstdio>#include<cstdlib>#include<algorithm>using namespace std;typedef long long ll;inline char nc(){static char buf[100000],*p1=buf,*p2=buf;if (p1==p2) { p2=(p1=buf)+fread(buf,1,100000,stdin); if (p1==p2) return EOF; }return *p1++;}inline void read(ll &x){char c=nc(),b=1;for (;!(c>='0' && c<='9');c=nc()) if (c=='-') b=-1;for (x=0;c>='0' && c<='9';x=x*10+c-'0',c=nc()); x*=b;}ll n,M,B,ans;ll X[100005];ll L,R,Mid,Sum,Road;inline bool TryRight(){if (R==n) return 0;ll last=Sum;Sum+=X[++R]-X[Mid];if (Mid!=(L+R)>>1){Mid++;Road=X[Mid]-X[Mid-1];Sum+=(Mid-1-L+1)*Road;Sum-=(R-Mid+1)*Road;}if (Sum>B) {Sum=last; R--; Mid=(L+R)>>1;return 0;}return 1;}int main(){freopen("t.in","r",stdin);freopen("t.out","w",stdout);read(n); read(M); read(B);for (int i=1;i<=n;i++) read(X[i]);R=1; L=1; Mid=1; Sum=0;while (TryRight());ans=max(ans,R-L+1);for (;L<n;){if (L==R){L++; R++; Sum=0; Mid=(L+R)>>1;}else{if (Mid==L){Mid++;Road=X[Mid]-X[Mid-1];Sum+=(Mid-1-L+1)*Road;Sum-=(R-Mid+1)*Road;}Sum-=X[Mid]-X[L++];if (Mid!=(L+R)>>1){Mid++;Road=X[Mid]-X[Mid-1];Sum+=(Mid-1-L+1)*Road;Sum-=(R-Mid+1)*Road;}}while (TryRight());ans=max(ans,R-L+1);}printf("%lld\n",ans);return 0;}

Race

很早做过的一道题 树分治裸题

#include<cstdio>#include<cstdlib>#include<algorithm>#include<functional>#include<queue>#define V G[p].vusing namespace std;typedef pair<int,int> abcd;inline char nc(){static char buf[100000],*p1=buf,*p2=buf;if (p1==p2) { p2=(p1=buf)+fread(buf,1,100000,stdin); if (p1==p2) return EOF; }return *p1++;}inline void read(int &x){char c=nc(),b=1;for (;!(c>='0' && c<='9');c=nc()) if (c=='-') b=-1;for (x=0;c>='0' && c<='9';x=x*10+c-'0',c=nc()); x*=b;}struct edge{int u,v,w;int next;};edge G[400005];int head[200005],num=1;inline void add(int u,int v,int w,int p){G[p].u=u; G[p].v=v; G[p].w=w; G[p].next=head[u]; head[u]=p;}inline void link(int u,int v,int w){add(u,v,w,++num); add(v,u,w,++num);}int n,K;int del[200005];int sum,size[200005];int minimum,rt;inline void Root(int u,int fa){int maximum=0;size[u]=1;for (int p=head[u];p;p=G[p].next)if (V!=fa && !del[V]){Root(V,u);size[u]+=size[V];maximum=max(maximum,size[V]);}maximum=max(maximum,sum-size[u]);if (maximum<minimum) minimum=maximum,rt=u;}int f[2000005];int ans;inline void dp(int u,int fa,int d,int len){if (K<d) return; ans=min(ans,f[K-d]+len);for (int p=head[u];p;p=G[p].next)if (!del[V] && V!=fa)dp(V,u,d+G[p].w,len+1);}inline void update(int u,int fa,int d,int len,int flag){if (K<d) return;if (flag)f[d]=min(f[d],len);else f[d]=n;for (int p=head[u];p;p=G[p].next)if (!del[V] && V!=fa)update(V,u,d+G[p].w,len+1,flag);}inline void solve(int u){del[u]=1; f[0]=0;for (int p=head[u];p;p=G[p].next)if (!del[V]){dp(V,u,G[p].w,1);update(V,u,G[p].w,1,1);}for (int p=head[u];p;p=G[p].next)if (!del[V])update(V,u,G[p].w,1,0);for (int p=head[u];p;p=G[p].next)if (!del[V]){minimum=n; sum=size[V]; Root(V,u);solve(rt);}}int main(){int _u,_v,_w;freopen("t.in","r",stdin);freopen("t.out","w",stdout);read(n); read(K);for (int i=1;i<n;i++)read(_u),read(_v),read(_w),link(_u+1,_v+1,_w);for (int i=1;i<=K;i++) f[i]=n; f[0]=0;ans=n;minimum=n; sum=n; Root(1,0);solve(rt);if (ans==n)printf("-1\n");else printf("%d\n",ans);return 0;}