POJ 3273 二分答案

思路：二分答案经典题吧。。。。注意边界就OK了

//By SiriusRen
#include <cstdio>
#include <algorithm>
using namespace std;
int n,m,a[100050],ans;
bool check(int x){
    int jy=0,temp=0;
    for(int i=1;i<=n;i++){
        if(a[i]+jy>x){
            jy=0;
            temp++;
            if(temp>m)return 0;
        }
        jy+=a[i];
        if(temp>=m||jy>x)return 0;
    }
    return 1;
}
int main(){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);
    int Left=0,Right=0x3fffffff;
    while(Left<=Right){
        int Mid=(Left+Right)>>1;
        if(check(Mid))Right=Mid-1,ans=Mid;
        else Left=Mid+1;
    }
    printf("%d
",ans);
}