Subsequence

http://poj.org/problem?id=3061 

 

 

 

 1 #include <iostream>
 2 #include <cstring>
 3 #include <cmath>
 4 #include <cstdio>
 5 #include <algorithm>
 6 using namespace std;
 7 #define LL long long
 8 const int maxn = 100010;
 9 const int inf = 0x3f3f3f3f;
10 LL a[maxn], b[maxn];
11 int main(){
12     int t;
13     //freopen("in.txt", "r", stdin);
14     scanf("%d", &t);
15     while(t--){
16         int n, s;
17         scanf("%d %d", &n, &s);
18         b[0] = 0;
19         for(int i = 1; i <= n; i++) {
20             scanf("%lld", &a[i]);
21             b[i] = b[i - 1] + a[i];
22         }
23         int ans = inf;
24         for(int i = 1; i <= n; i++){
25             if(b[i] < s) continue;
26             int temp = b[i] - s;
27             int id = lower_bound(b + 1, b + 1 + n, temp) - b;
28             if(b[id] == temp) while(b[id + 1] == temp) id++;
29             else{
30                 id--;
31             }
32             //cout<<i<<"  ----------  "<<id<<" =++"<<endl;
33             ans = min(ans, i - id);
34         }
35         if(ans == inf) ans = 0;
36         printf("%d\n", ans);
37     }
38 }
View Code

 

尺取～

 

 1 #include <iostream>
 2 #include <cstring>
 3 #include <cmath>
 4 #include <cstdio>
 5 #include <algorithm>
 6 using namespace std;
 7 #define LL long long
 8 const int maxn = 100010;
 9 const int inf = 0x3f3f3f3f;
10 LL a[maxn];
11 int main(){
12     int t;
13     //freopen("in.txt", "r", stdin);
14     scanf("%d", &t);
15     while(t--){
16         int n, s;
17         scanf("%d %d", &n, &s);
18         for(int i = 0; i < n; i++) scanf("%lld", &a[i]);
19         int i = 0, j = 0;
20         int sum = 0;
21         int ans = inf;
22         while(1){
23             while(sum < s && j < n) sum += a[j++];
24             if(sum < s) break;
25             ans = min(ans, j - i);
26             sum -= a[i++];
27         }
28         if(ans == inf) ans = 0;
29         printf("%d\n", ans);
30     }
31 }
View Code

 

posted @ 2017-12-02 21:17  yijiull  阅读(151)  评论(0)  编辑  收藏  举报