hdu4648Magic Pen 6

http://acm.hdu.edu.cn/showproblem.php?pid=4648

求连续的一段和对m取余为0  若s[j]和s[i]对M的余数都相同 则相见就满足要求 找个最长的

 1 #include <iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<stdlib.h>
 6 using namespace std;
 7 #define LL long long
 8 #define N 100010
 9 #define INF 0xfffffff
10 LL s[N];
11 int a[N],d1[N],d2[N];
12 int main()
13 {
14     int i,j,n,m,k;
15     while(cin>>n>>m)
16     {
17         memset(s,0,sizeof(s));
18         LL sum=0;
19         for(i = 1; i <= m ; i++)
20         {
21             d1[i] = -INF;
22             d2[i] = INF;
23         }
24         int ans=0;
25         for(i = 1; i <= n ; i++)
26         {
27             scanf("%d",&a[i]);
28             sum+=a[i];
29             s[i] = s[i-1]+a[i];
30             k = s[i]%m;
31             if(k<0) k+=m;
32             if(k==0)
33             ans = max(ans,i);
34             d1[k] = max(d1[k],i);
35             d2[k] = min(d2[k],i);
36         }
37         for(i = 1; i < m ; i++)
38         ans = max(d1[i]-d2[i],ans);
39         cout<<ans<<endl;
40     }
41     return 0;
42 }
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posted @ 2013-08-07 09:18  _雨  阅读(198)  评论(0)  编辑  收藏  举报