洛谷 P1569 [USACO11FEB]属牛的抗议Generic Cow Prote…

题目传送门

解题思路:

f[i]表示i为末尾的最大组数.

AC代码:

 1 #include<iostream>
 2 #include<cstdio>
 3 
 4 using namespace std;
 5 
 6 long long n,a[1001],sum,f[1001],num[1001];
 7 
 8 int main() {
 9     scanf("%lld",&n);
10     for(int i = 1;i <= n; i++) {
11         scanf("%lld",&a[i]);
12         sum += a[i];
13         num[i] = num[i-1] + a[i];
14     }
15     if(sum < 0) {
16         printf("Impossible");
17         return 0;
18     }
19     for(int i = 1;i <= n; i++) {
20         if(num[i] >= 0)
21             f[i] = 1;
22         for(int j = 0;j < i; j++) {
23             if(f[j] > 0 && num[i] - num[j] >= 0)
24                 f[i] = max(f[i],f[j] + 1);
25         }
26     }
27     printf("%lld",f[n]);
28     
29     return 0;
30 }