poj2593

同poj2479几乎一致。。

http://www.cnblogs.com/yzcstc/archive/2013/03/23/2977529.html

 1 /*
 2  Author:yzcstc
 3  State:Accept
 4  Time:2013.2.26
 5 */
 6 #include <iostream>
 7 #include <cstdlib>
 8 #include <cstdio>
 9 #include <cmath>
10 #include <cstring>
11 #include <string>
12 #include <algorithm>
13 using namespace std;
14 const int minn = -500000001;
15 int T , n , a[100005], lsum[3][100005], rsum[3][100005] , ans;
16 
17 void dp(){
18       ans = minn;
19       lsum[0][0] = lsum[1][0] = minn;
20       rsum[0][n + 1] = rsum[1][n + 1] = minn;
21       for (int i = 1; i <= n; ++i)
22         {
23             scanf("%d",&a[i]);
24             lsum[0][i] = max(lsum[0][i - 1] + a[i] , a[i]);
25             lsum[1][i] = max(lsum[1][i - 1] , lsum[0][i - 1]);
26         }
27 
28       for (int i = n; i >= 1; --i)
29          {
30 
31             rsum[0][i] = max(rsum[0][i + 1] + a[i] , a[i]);
32             rsum[1][i] = max(rsum[1][i + 1] , rsum[0][i + 1]);
33          }
34       for (int i = 2; i <= n; ++i)
35             ans = max( ans , 
36             max(lsum[0][i - 1], lsum[1][i - 1]) + max( rsum[0][i] , rsum[1][i]));
37 }
38 
39 int main(){
40       freopen("poj2593.in","r",stdin);
41       freopen("poj2593.out","w",stdout);
42       scanf("%d",&n);
43       while (n)
44         {
45              dp();
46              printf("%d\n",ans); 
47              scanf("%d",&n);
48              
49         }
50       fclose(stdin); fclose(stdout);
51 }

 

 

 

posted on 2013-03-23 19:00  yzcstc  阅读(135)  评论(0)  编辑  收藏  举报