CF——#182div2B

B题地址：http://codeforces.com/contest/302/problem/B

注：好坑啊二分啊。

#include<iostream>

#include<cstring>#include<queue>#include<cstdio>#include<cmath>#include<algorithm>using namespace std;#define N 100005int a[N];int main(){    int n,m;    int i,j,k;    while(cin>>n>>m)    {    int st=0;    int num1,num2;    int mid;    a[0]=0;    for(i=1;i<=n;i++)     { cin>>num1>>num2; a[i]=st+num1*num2; st=a[i];     }     while(m--)     {     cin>>num1;     int top=n;     int bottom=0;     int mid;      while(bottom<=top)      {     mid=(top+bottom)/2;     if(a[mid]<num1&&a[mid+1]>=num1)  { cout<<mid+1<<endl; break; }     if(a[mid]<num1) bottom=mid+1;     else top=mid-1;     }        }          }return 0;}