codeforces 368(div 2)前三题

第一题
很多人没看到G，被坑了

#include<cstdio>#include<iostream>int main(){    int n,m;    char x,y;    scanf("%d%d\n",&n,&m);    bool ok = 1;    for (int i=1;i<=n;i++){        for (int j=1;j<=m;j++){            scanf("%c%c",&x,&y);            if (x=='C'||x=='M'||x=='Y')ok = 0;        }    }    if (ok)puts("#Black&White");    else puts("#Color");}

第二题，
a[i]=1表示i位置是个仓库
然后按边的权值排序,找一条边两个点一个是仓库一个不是仓库的

#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;const int N=1e5 + 10;struct Edge{    int x,y,w;    Edge(){}    Edge(int _x,int _y,int _w):x(_x),y(_y),w(_w){}    bool operator < (Edge a)const {        return w < a.w ;    }}edges[N];int a[N];int main(){    int n,m,k,x,y,z;    scanf("%d%d%d",&n,&m,&k);    for (int i=1;i<=m;i++){        scanf("%d%d%d",&x,&y,&z);        edges[i]=Edge(x,y,z);    }    if (k==0)puts("-1");    else {        memset(a,0,sizeof(a));        for (int i=1;i<=k;i++){            scanf("%d",&x);a[x]=1;        }        sort(edges+1,edges+m+1);        int ans = -1;        for (int i=1;i<=m;i++){            if (a[edges[i].x]^a[edges[i].y]){                ans = edges[i].w;break;            }        }        printf("%d\n",ans);    }    return 0;}

第三题

找勾股数。。。分类讨论就行了

#include<cstdio>#include<iostream>using namespace std;int main(){    long long n;    cin >> n;    if (n==1 ||n==2 )puts("-1");    else {        if (n&1){            n *= n ;            printf("%I64d %I64d\n",(n-1)>>1,(n+1)>>1);        }        else {            n >>= 1 ;            printf("%I64d %I64d\n",n*n-1,n*n+1);        }    }    return 0;}

第四题

听说是主席树

可持久化数据结构
承旭老师说rope可以秒，

http://blog.csdn.net/iamzky/article/details/38348653

暴力修改版本的，，，TLE的死死的

#include<cstdio>#include<string>#include<cstring>#include<iostream>#include<algorithm>#include<ext/rope>using namespace std;using namespace __gnu_cxx;const int N=1e5 + 10;struct node{    int pos,num;    string a;    node(){}    node(int x,int y,string st){        pos=x,num=y,a=st;    }}bo;rope <node> *book[N];int ans[N];int main(){    //freopen("fuck.in","r",stdin);    int n,m,q,x,y,ord,tot=0;    scanf("%d%d%d",&n,&m,&q);    string zero = "";    for (int i=1;i<=m;i++)zero+="0";    book[0]=new rope<node>();    book[0]->push_back(node(0,0,""));    for (int i=1;i<=n;i++)        book[0]->push_back(node(i,0,zero));    for (int ti=1;ti<=q;ti++){        book[ti] = new rope <node>(*book[ti-1]);        ans[ti] = ans[ti-1];        scanf("%d%d",&ord,&x);        if (ord==1){            scanf("%d",&y);            bo = book[ti]->at(x);            if (bo.a[y-1]=='0'){                bo.a[y-1]='1';                bo.num++;                book[ti]->replace(x,bo);                ans[ti]++;            }        }else if (ord==2){            scanf("%d",&y);            bo = book[ti]->at(x);            if (bo.a[y-1]=='1'){                bo.a[y-1]='0';                bo.num--;                book[ti]->replace(x,bo);                ans[ti]--;            }        }else if (ord==3){            bo = book[ti]->at(x);            for (int i=0;i<m;i++){                bo.a[i]=(bo.a[i]=='1')?'0':'1';            }            bo.num = m - bo.num;            book[ti]->replace(x,bo);            bo = book[ti]->at(0);            ans[ti] += m - bo.num*2 ;        }else if (ord==4){            book[ti]= book[x];            ans[ti] = x;        }        printf("%d\n",ans[ti]);    }    return 0;}

承旭老师改出个优雅的修改个版本的
MLE了

#include<cstdio>#include<string>#include<cstring>#include<iostream>#include<algorithm>#include<ext/rope>using namespace std;using namespace __gnu_cxx;const int N=1e5+5,M=1e3+5;struct node{    int num;    bool a[M],re;    node(){}}bo;rope <node> *book[N];int ans[N];int main(){    //freopen("fuck.in","r",stdin);    int n,m,q,x,y,ord;    book[0]=new rope<node>();    scanf("%d%d%d",&n,&m,&q);    for (int i=0;i<n;i++)        book[0]->insert(i,bo);    for (int ti=1;ti<=q;ti++){        scanf("%d%d",&ord,&x);        if (ord==4){            book[ti] = new rope <node>(*book[x]);            ans[ti]=ans[x];        }else{            book[ti] = new rope <node>(*book[ti-1]);            ans[ti]=ans[ti-1];        }        if (ord==1){            scanf("%d",&y);            bo=book[ti]->at(x-1);            if (bo.a[y-1]^bo.re==0){                bo.a[y-1]^=1;                bo.num ++;                book[ti]->replace(x-1,bo);                ans[ti]++;            }        }        if (ord==2){            scanf("%d",&y);            bo=book[ti]->at(x-1);            if (bo.a[y-1]^bo.re==1){                bo.a[y-1]^=1;                bo.num --;                book[ti]->replace(x-1,bo);                ans[ti]--;            }        }        if (ord==3){            bo=book[ti]->at(x-1);            bo.re^=1;            ans[ti]+=m - bo.num*2;            bo.num = m - bo.num;            book[ti]->replace(x-1,bo);        }        printf("%d\n",ans[ti]);    }    return 0;}

搞出个树套树

TLE,要疯了

#include<cstdio>#include<string>#include<cstring>#include<iostream>#include<algorithm>#include<ext/rope>using namespace std;using namespace __gnu_cxx;const int N=1e5 + 10,M=10e3+5;rope <rope<bool>* > *book[N];rope<bool> *tmp,*re[N];rope<int> *num[N];int ans[N];int main(){   // freopen("1.in","r",stdin);  //  freopen("1.out","w",stdout);    int n,m,q,x,y,ord;    book[0]=new rope<rope<bool>* >();    tmp=new rope<bool>();    num[0]=new rope<int>();    re[0]=new rope<bool>();    scanf("%d%d%d",&n,&m,&q);    for (int i=0;i<m;i++)        tmp->insert(i,false);    for (int i=0;i<n;i++){        tmp=new rope<bool>(*tmp);        book[0]->insert(i,tmp);        num[0]->insert(i,0);        re[0]->insert(i,false);    }    for (int ti=1;ti<=q;ti++){        scanf("%d%d",&ord,&x);     //   printf("%d: %d %d\n",ti,ord,x);        if (ord==4){            book[ti] = new rope <rope<bool>* >(*book[x]);            num[ti] = new rope<int>(*num[x]);            re[ti] = new rope<bool>(*re[x]);            ans[ti]=ans[x];        }else{            book[ti] = new rope <rope<bool>* >(*book[ti-1]);            num[ti] = new rope<int>(*num[ti-1]);            re[ti] = new rope<bool>(*re[ti-1]);            ans[ti]=ans[ti-1];        }        if (ord==1){            scanf("%d",&y);            tmp=book[ti]->at(x-1);            bool f=tmp->at(y-1),flag=re[ti]->at(x-1);            if (f^flag==0){                tmp=new rope<bool>(*tmp);                f^=1;                tmp->replace(y-1,f);                book[ti]->replace(x-1,tmp);                int nu=num[ti]->at(x-1);                nu++;                num[ti]->replace(x-1,nu);                ans[ti]++;            }        }        if (ord==2){            scanf("%d",&y);            tmp=book[ti]->at(x-1);            bool f=tmp->at(y-1),flag=re[ti]->at(x-1);            if (f^flag==1){                tmp=new rope<bool>(*tmp);                f^=1;                tmp->replace(y-1,f);                book[ti]->replace(x-1,tmp);                int nu=num[ti]->at(x-1);                nu--;                num[ti]->replace(x-1,nu);                ans[ti]--;            }        }        if (ord==3){            re[ti]->replace(x-1,re[ti]->at(x-1)^1);            //printf("%d %d\n",bo.num,bo.cnt);            ans[ti]+=m - num[ti]->at(x-1)*2;            num[ti]->replace(x-1,m-num[ti]->at(x-1));        }      /*  for (int i=0;i<n;i++){            tmp=book[0]->at(i);            for (int j=0;j<m;j++){                bool f=tmp->at(j);                printf("%d ",f^re[0]->at(i));            }            puts("");        }*/        printf("%d\n",ans[ti]);    }    return 0;}

丧心病狂的STL
http://tieba.baidu.com/p/2215390730