tjut 5396

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#include<stdio.h>#include<string.h>#include<algorithm>#include<iostream>#include<vector>#include<queue>#include<cmath>using namespace std;#define INF 0x3fffffff#define maxn 110typedef long long LL;const LL MOD = 1e9+7;LL A[maxn], C[maxn][maxn];char op[maxn];LL dp[maxn][maxn];int main(){    int n;    A[0] = 1;    for(int i=1; i<=100; i++)        A[i] = (A[i-1] * i)%MOD;    C[0][0] = 1;    for(int i=1; i<=100; i++)    {        C[i][0] = 1;        for(int j=1; j<=i; j++)            C[i][j] = (C[i-1][j-1] + C[i-1][j])%MOD;    }    while(scanf("%d", &n) != EOF)    {        memset(dp, 0, sizeof(dp));        for(int i=1; i<=n; i++)            scanf("%I64d", &dp[i][i]);        scanf("%s", op+1);        for(int L=2; L <= n; L++)        {            for(int i=1; i+L-1 <= n; i++)            {                int j = i + L - 1;                dp[i][j] = 0;                for(int k=i; k<j; k++)                {                    LL t;                    if(op[k] == '*')                        t = (dp[i][k] * dp[k+1][j])%MOD;                    if(op[k] == '+')                        t = (dp[i][k]*A[j-k-1] + dp[k+1][j]*A[k-i])%MOD;                    if(op[k] == '-')                        t = (dp[i][k]*A[j-k-1] - dp[k+1][j]*A[k-i])%MOD;                    dp[i][j] = (dp[i][j] + t * C[j-i-1][k-i])%MOD;                }            }        }        printf("%I64d\n", (dp[1][n]+MOD)%MOD );    }    return 0;}
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