hdu 4004 二分+ 贪心 The Frog's Games

#include <iostream>
#include <cstdio>
#include <algorithm>

using namespace std;
int l,m,n,dis[500010],ant[500010];
bool go(int dist){
int pre = ant[1]; int num = 1;
if(pre > dist) return false;
for(int i = 2; i <= n + 1; i ++){
if(pre + ant[i] > dist){pre = ant[i]; num ++;}
else pre += ant[i];
if(num > m) return false;
}
return true;
}
int main(){
while(~scanf("%d%d%d",&l,&n,&m)){
for(int i = 1; i <= n; i ++)
scanf("%d",dis + i);
sort(dis + 1, dis + 1 + n);

dis[n + 1] = l; dis[0] = 0;
int Max = 0;
for(int i = 1; i <= n + 1; i ++){
ant[i] = dis[i] - dis[i - 1];
Max = max(ant[i],Max);
}
//        cout << Max << endl;
int low = Max, high = l;
while(low <= high){
int mid = (low + high) >> 1;
if(go(mid)) high = mid - 1;
else low = mid + 1;
}
printf("%d\n",low);
}
return 0;
}