2016 Multi-University Training Contest 5 1011 Two DP

http://acm.hdu.edu.cn/showproblem.php?pid=5791

HDU5791 Two

题意 ：两个数组，多少个不连续子串相等

思路：

dp[i][j] ：a串i结尾，b串j结尾的不连续子串数目个数

 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<iostream>
 using namespace std;
 typedef long long ll;
 const int maxn=1e3+;
 const int mod=1e9+;
 const int inf=0x3f3f3f3f;
 ll dp[maxn][maxn],a[maxn],b[maxn];
 int n,m;
 int main(){
     while(~scanf("%d%d",&n,&m)){
         for(int i=;i<=n;i++)scanf("%lld",&a[i]);
         for(int i=;i<=m;i++)scanf("%lld",&b[i]);
         memset(dp,,sizeof(dp));
         for(int i=;i<=n;i++){
             for(int j=;j<=m;j++){
                 dp[i][j]=(dp[i-][j]+dp[i][j-]-dp[i-][j-]+(a[i]==b[j]?dp[i-][j-]+:)+mod)%mod;
             }
         }
         printf("%lld\n",dp[n][m]);
     }
     return ;
 }