codeforces732D Exams（贪心+二分）

题意

不可描述

思路

二分答案，贪心判断

代码

/* ********************************Author          : danmuCreated Time    : 2016年11月10日 星期四 10时19分02秒File Name       : a.cpp******************************** */#include <algorithm>#include <iostream>#include <cstdlib>#include <cstring>#include <iomanip>#include <string>#include <vector>#include <cstdio>#include <stack>#include <queue>#include <cmath>#include <list>#include <map>#include <set>#define rep(i,x,y) for(int i=x;i<=y;++i)#define _rep(i,x,y) for(int i=x;i>=y;--i)#define CL(S,x) memset(S,x,sizeof(S))#define CP (S1,S2) memcpy(S1,S2,sizeof(S2))#define ALL(x,S) for(x=S.begin();x!=S.end();++x)#define ULL unsigned long long#define PI 3.1415926535#define INF 0x3f3f3f3f#define LL long longconst int maxn = 1e5;const int mod = 1e9 + 7;const double eps = 1e-8;using namespace std;int a[maxn+5],b[maxn+5];bool flag[maxn+5];int n,m;bool judge(int x){    LL tmp=0;    memset(flag,0,sizeof flag);    for(int i=x;i>=1;--i){        if(b[i]&&!flag[b[i]]){            tmp+=a[b[i]];            flag[b[i]]=true;        }        else if(tmp>0) --tmp;    }    for(int i=1;i<=m;++i)        if(!flag[i])            return false;    printf("%d %lld\n",x,tmp);    if(tmp>0) return false;    return true;}int main(){    //freopen("in.txt", "r", stdin);    //freopen("out.txt", "w", stdout);    int l,r,mid;    scanf("%d%d",&n,&m);    for(int i=1;i<=n;++i)        scanf("%d",b+i);    for(int i=1;i<=m;++i)        scanf("%d",a+i);    l=0,r=n+1;    while(r-l>1){        mid=(l+r)>>1;        if(judge(mid))            r=mid;        else            l=mid;    }    printf("%d\n",r==n+1?-1:r);    return 0;}