POJ-3273 Monthly Expense---最小化最大值

 1 #include<iostream>
 2 #include<cstdio>
 3 using namespace std;
 4 typedef long long ll;
 5 const int maxn = 1e6 + 10;
 6 int n, m;
 7 int a[maxn];
 8 bool judge(int x)
 9 {
10     int tot = 0, cnt = 1;
11     for(int i = 1; i <= n; i++)
12     {
13         if(tot + a[i] > x)
14         {
15             tot = a[i];
16             cnt++;
17         }
18         else tot += a[i];
19     }
20     //cout<<x<<":::"<<cnt<<endl;
21     return cnt <= m;
22 }
23 int main()
24 {
25     while(cin >> n >> m){
26     int l = 0, r = 0, ans;
27     for(int i = 1; i <= n; i++)
28         scanf("%d", &a[i]), r += a[i], l = max(l, a[i]);
29     //l 和 r的范围必须确定好
30 
31     while(l <= r)
32     {
33         int mid = (l + r) / 2;
34         if(judge(mid))
35             ans = mid, r = mid - 1;
36         else l = mid + 1;
37     }
38     cout<<ans<<endl;
39     }
40     return 0;
41 }