hdu 5791 dp简单

来源：互联网发布：tiny core linux 中文编辑：程序博客网时间：2024/06/01 17:55

分析

模拟序列添加的过程即可。

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>using namespace std;#define pr(x) cout << #x << ": " << x << "  " #define pl(x) cout << #x << ": " << x << endl;struct jibancanyang{    int n, m;    int A[1009], B[1008];    long long dp[1009][1009];    int mod = int(1e9) + 7;    void fun() {        while (~scanf("%d%d", &n, &m)) {            for (int i = 1; i <= n; ++i) scanf("%d", &A[i]);            for (int j = 1; j <= m; ++j) scanf("%d", &B[j]);            A[0] = B[0] = 0;            memset(dp, 0, sizeof(dp));            for (int i = 1; i <= n; ++i) {                for (int j = 1; j <= m; ++j) {                    dp[i][j] = dp[i - 1][j] + dp[i][j - 1] - dp[i - 1][j - 1];                    if (A[i] == B[j]) dp[i][j] +=  dp[i - 1][j - 1] + 1;                    dp[i][j] = (dp[i][j] % mod + mod) % mod;                }            }            printf("%lld\n", dp[n][m]);        }    }}ac;int main(){#ifdef LOCAL    freopen("in.txt", "r", stdin);    //freopen("out.txt", "w", stdout);#endif    ac.fun();    return 0;}

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