很裸的$dp+$组合计数
注意
注意
注意
$BZOJ$不要用玄学优化
$CE$不管$qwq$
/************************************************************** Problem: 1801 User: zhangheran Language: C++ Result: Accepted Time:196 ms Memory:11692 kb ****************************************************************/ //#pragma GCC optimize(2) //#pragma GCC optimize(3) //#pragma GCC optimize("Ofast") //#pragma GCC optimize("inline") //#pragma GCC optimize("-fgcse") //#pragma GCC optimize("-fgcse-lm") //#pragma GCC optimize("-fipa-sra") //#pragma GCC optimize("-ftree-pre") //#pragma GCC optimize("-ftree-vrp") //#pragma GCC optimize("-fpeephole2") //#pragma GCC optimize("-ffast-math") //#pragma GCC optimize("-fsched-spec") //#pragma GCC optimize("unroll-loops") //#pragma GCC optimize("-falign-jumps") //#pragma GCC optimize("-falign-loops") //#pragma GCC optimize("-falign-labels") //#pragma GCC optimize("-fdevirtualize") //#pragma GCC optimize("-fcaller-saves") //#pragma GCC optimize("-fcrossjumping") //#pragma GCC optimize("-fthread-jumps") //#pragma GCC optimize("-funroll-loops") //#pragma GCC optimize("-fwhole-program") //#pragma GCC optimize("-freorder-blocks") //#pragma GCC optimize("-fschedule-insns") //#pragma GCC optimize("inline-functions") //#pragma GCC optimize("-ftree-tail-merge") //#pragma GCC optimize("-fschedule-insns2") //#pragma GCC optimize("-fstrict-aliasing") //#pragma GCC optimize("-fstrict-overflow") //#pragma GCC optimize("-falign-functions") //#pragma GCC optimize("-fcse-skip-blocks") //#pragma GCC optimize("-fcse-follow-jumps") //#pragma GCC optimize("-fsched-interblock") //#pragma GCC optimize("-fpartial-inlining") //#pragma GCC optimize("no-stack-protector") //#pragma GCC optimize("-freorder-functions") //#pragma GCC optimize("-findirect-inlining") //#pragma GCC optimize("-fhoist-adjacent-loads") //#pragma GCC optimize("-frerun-cse-after-loop") //#pragma GCC optimize("inline-small-functions") //#pragma GCC optimize("-finline-small-functions") //#pragma GCC optimize("-ftree-switch-conversion") //#pragma GCC optimize("-foptimize-sibling-calls") //#pragma GCC optimize("-fexpensive-optimizations") //#pragma GCC optimize("-funsafe-loop-optimizations") //#pragma GCC optimize("inline-functions-called-once") //#pragma GCC optimize("-fdelete-null-pointer-checks") //#include"suqingnian.h" #include<iostream> #include<cstdio> #include<algorithm> using namespace std; const int mod=9999973; long long dp[110][110][110]; int n,m;long long ans; long long calc(long long xx) {return xx*(xx-1)/2;} int main() { scanf("%d%d",&n,&m); dp[0][0][0]=1; for(int i=0;i<n;i++) for(int j=0;j<=m;j++) for(int k=0;k<=m-j;k++) if(dp[i][j][k]){ if(j-2>=0) dp[i+1][j-2][k+2]=(dp[i+1][j-2][k+2]+dp[i][j][k]*calc(j))%mod; if(j-1>=0) dp[i+1][j-1][k+1]=(dp[i+1][j-1][k+1]+dp[i][j][k]*j)%mod; dp[i+1][j][k]=(dp[i+1][j][k]+dp[i][j][k])%mod, dp[i+1][j][k+1]=(dp[i+1][j][k+1]+dp[i][j][k]*(m-j-k)*j)%mod, dp[i+1][j+1][k]=(dp[i+1][j+1][k]+dp[i][j][k]*(m-j-k))%mod, dp[i+1][j+2][k]=(dp[i+1][j+2][k]+dp[i][j][k]*calc(m-j-k))%mod; // printf("%d %d %d %d ",i,j,k,dp[i][j][k]); } for(int i=0;i<=m;i++) for(int j=0;j<=m-i;j++) // printf("%lld ",dp[n][i][j]); ans=(ans+dp[n][i][j])%mod; printf("%lld ",ans%mod); }