HDU 4832 chess

It is also a question of Baidu star.
When I first read the question and thought it was a search question, I came up with the idea of finding a question. There was no fighting spirit at the beginning, and of course this question would not be made.

However, after reading the question, I suddenly realized that it was originally DP, and it was a very simple DP.
Another failure indicates that it is not a good habit to look at the problem. I want to change it! I want to change it !!

In fact, the basic idea is to separate the two-dimensional movement into one-dimensional movement, and then add the combination number.

The following is the code. Although it was typed by myself, it is still plagiarized ....

#include <iostream>#include <cstdio>#include <cstring>using namespace std;const int mod = 9999991;const int maxn = 1010;#define LL long longLL sum[2][maxn], dp[2][maxn][maxn];LL C[1010][1010];void init(){    memset(sum, 0, sizeof(sum));    memset(dp, 0, sizeof(dp));    for(int i = 0; i < maxn; i++)        C[i][i] = 1, C[i][0] = 1;    for(int i = 2; i < maxn; i++)        for(int j = 1; j < i; j++)            C[i][j] =(C[i-1][j] + C[i-1][j-1]) % mod;}void solve(int n, int k, int t, int p){    dp[p][0][t] = 1;    sum[p][0] = 1;    for(int i = 1; i <= k; i++)    {        for(int j = 1; j <= n; j++)        {            if(j - 1 > 0)  dp[p][i][j] += dp[p][i-1][j-1];            if(j - 2 > 0)  dp[p][i][j] += dp[p][i-1][j-2];            if(j + 1 <= n) dp[p][i][j] += dp[p][i-1][j+1];            if(j + 2 <= n) dp[p][i][j] += dp[p][i-1][j+2];            dp[p][i][j] %= mod;            sum[p][i] = (sum[p][i] + dp[p][i][j]) % mod;        }    }    return ;}LL getans(int k){    LL ans = 0;    for(int i = 0; i <= k; i++)        ans = ans + (((C[k][i] * sum[1][i]) % mod) * sum[0][k - i]) % mod;    return ans % mod;}int main(){    int t, n, m, k, x, y;    cin >> t;    for(int Case = 1; Case <= t; Case++)    {        scanf("%d%d%d%d%d", &n, &m, &k, &x, &y);        init();        solve(n,k,x,0);        solve(m,k,y,1);        printf("Case #%d:\n%I64d\n", Case, getans(k));    }}

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