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,&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
",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-1)>>1,(n+1)>>1);
        }
        else {
            n >>= 1 ;
            printf("%I64d %I64d
",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
",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
",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
",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
",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
",ans[ti]);
    }
    return 0;
}

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