POJ 3273 Monthly Expense 二分枚举

题目：http://poj.org/problem?id=3273

二分枚举，据说是经典题，看了题解才做的，暂时还没有完全理解。。

 #include <stdio.h>
 #include <string.h>
 
 int n, m;
 int a[];
 
 bool judge(int x)
 {
     int money = , cnt = ;
     for(int i = ; i < n; i++)
     {
         if(money + a[i] <= x)
             money += a[i];
         else
         {
             money = a[i];
             cnt++;
         }
     }
     if(cnt > m)
         return ;
     else return ;
 }
 
 int main()
 {
     int low = , high = ;
     scanf("%d %d", &n, &m);
     for(int i = ; i < n; i++)
     {
         scanf("%d", &a[i]);
         if(low < a[i])
             low = a[i];
         high += a[i];
     }
     int mid = (low + high) / ;
     while(low < high)
     {
         if(judge(mid))
             high = mid - ;
         else low = mid + ;
         mid = (low + high) / ;
     }
     printf("%d\n", mid);
     return ;
 }