Colorful Board Lightoj 思考一周多后的灵感

#include<stdio.h>#include<string.h> typedef long long lld;const int mod=1000000007;const int maxn=55;lld dp[maxn][maxn][maxn];//dp[i][j][k]前i种颜色,奇的格子为j，偶的格子为k void init(){    int i,j,k;    memset(dp,0,sizeof(dp));    dp[0][0][0]=1;    for(i=1;i<=50;i++)        for(j=0;j<=50;j++)            for(k=0;k<=50;k++){                dp[i][j][k]+=dp[i-1][j][k];                dp[i][j+1][k]+=dp[i-1][j][k];                dp[i][j][k+1]+=dp[i-1][j][k];                 dp[i][j][k]%=mod;                dp[i][j+1][k]%=mod;                dp[i][j][k+1]%=mod;            }}int n,m,g;//次dp求len长度的不同格子，用k种颜色图的方案数，每种颜色至少用一次lld p[205][maxn];//DP[i][j]表示长度为i用了j种颜色的方案数lld Gao(int tot,int len){    int i,j,k;    memset(p,0,sizeof(p));    p[0][0]=1;    for(i=0;i<len;i++)for(j=0;j<=i && j<=tot ;j++){p[i+1][j]=(p[i+1][j]+p[i][j]*j)%mod;if(j<tot)p[i+1][j+1]=(p[i+1][j+1]+p[i][j]*(tot-j))%mod;}    return p[len][tot];}lld J[205][maxn];void Kao(){for(int i=1;i<=200;i++){for(int j=1;j<maxn;j++)J[i][j]=Gao(j,i);}}int main(){    int T;    int i,j;    int even,odd;    lld ans;    init();Kao();    scanf("%d",&T);    for(int cas=1;cas<=T;cas++){        scanf("%d%d%d",&n,&m,&g);        if(n+m==0){            printf("Case %d: %d\n",cas,g);            continue;        }        ans=0;        n++;m++;        even=odd=0;        for(i=1;i<=n;i++)            for(j=1;j<=m;j++)                if((i+j)%2)odd++;                else even++;        for(i=1;i<=g;i++)            for(j=1;j+i<=g;j++){                lld tp=J[odd][i]*J[even][j]%mod;                ans=(ans+ (dp[g][i][j]*tp)%mod)%mod;            }        printf("Case %d: %lld\n",cas,ans);    }    return 0;}