dp HDU

按题意推表达式

#include<cstdio>
#include<cstring>
#define max(a, b) (a)>(b)?(a):(b)

int dp[105][105], num[105][105], a[105];

int main()
{
    int t;
    scanf("%d", &t);
    while (t--)
    {
        int n, m;
        scanf("%d%d", &n, &m);
        for (int i = 1; i <= m;++i)
        for (int j = 1; j <= m; ++j)
            scanf("%d", &num[i][j]);
        for (int i = 1; i <= n; ++i)scanf("%d", &a[i]);
        for (int i = 2; i <= n; ++i)
        {
            if (a[i - 1] > 0 && a[i] > 0)dp[i][a[i]] = dp[i - 1][a[i - 1]] + num[a[i - 1]][a[i]];
            else if (a[i - 1]<0 && a[i]>0)
            {
                for (int k = 1; k <= m; ++k)
                    dp[i][a[i]] = max(dp[i][a[i]], dp[i - 1][k] + num[k][a[i]]);
            }
            else if (a[i - 1] > 0 && a[i] < 0)
            {
                for (int k = 1; k <= m; ++k)
                    dp[i][k] = max(dp[i][k], dp[i - 1][a[i - 1]] + num[a[i - 1]][k]);
            }
            else
            {
                for (int k = 1; k <= m;++k)
                for (int j = 1; j <= m; ++j)
                    dp[i][k] = max(dp[i][k], dp[i - 1][j] + num[j][k]);
            }
        }
        int ans = 0;
        for (int i = 1; i <= m; ++i)
            ans = max(ans, dp[n][i]);
        printf("%d
", ans);