求助各位大佬,tle了,时间复杂度也正确,已使出全身解数都没有卡过,求助各位大佬。
代码:
#pragma GCC optimize(3)
#pragma GCC target("avx")
#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")
#pragma GCC optimize(2)
#include<bits/stdc++.h>
#define int __int128
using namespace std;
const int p=998244353;
int n,k,f[260][260];
int c[260][260];
int sum[260][260];
inline int read() {
int X=0;
bool flag=1;
char ch=getchar();
while(ch<'0'||ch>'9') {
if(ch=='-') flag=0;
ch=getchar();
}
while(ch>='0'&&ch<='9') {
X=(X<<1)+(X<<3)+ch-'0';
ch=getchar();
}
if(flag) return X;
return ~(X-1);
}
inline void write(int X) {
if(X<0) {
X=~(X-1);
putchar('-');
}
if(X>9) write(X/10);
putchar(X%10+'0');
}
inline int qpow(int x,int y) {
int r=1;
while(y) {
if(y&1) r=r*x%p;
x=x*x%p,y>>=1;
}
return r;
}
signed main() {
n=read();
k=read();
f[1][0]=1;
for(register int i=0; i<=k; ++i) {
sum[1][i]=1;
}
for(register int i=0; i<=n; ++i) {
c[i][0]=1;
}
for(register int i=1; i<=n; ++i) {
for(register int j=1; j<=i; ++j) {
c[i][j]=(c[i-1][j-1]+c[i-1][j])%p;
}
}
for(register int i=2; i<=n; ++i) {
for(register int j=1; j<=k; ++j) {
for(register int t=1; t<=i-1; t+=10) {
f[i][j]=(f[i][j]+c[n-t][i-t]*sum[t][j-1]%p*qpow(k-j+1,(i-2+t-1)*(i-t)/2)%p)%p;//原始式子是这个,下面是循环展开
if(t+1<=i-1) f[i][j]=(f[i][j]+c[n-(t+1)][i-(t+1)]*sum[(t+1)][j-1]%p*qpow(k-j+1,(i-2+(t+1)-1)*(i-(t+1))/2)%p)%p;
if(t+2<=i-1) f[i][j]=(f[i][j]+c[n-(t+2)][i-(t+2)]*sum[(t+2)][j-1]%p*qpow(k-j+1,(i-2+(t+2)-1)*(i-(t+2))/2)%p)%p;
if(t+3<=i-1) f[i][j]=(f[i][j]+c[n-(t+3)][i-(t+3)]*sum[(t+3)][j-1]%p*qpow(k-j+1,(i-2+(t+3)-1)*(i-(t+3))/2)%p)%p;
if(t+4<=i-1) f[i][j]=(f[i][j]+c[n-(t+4)][i-(t+4)]*sum[(t+4)][j-1]%p*qpow(k-j+1,(i-2+(t+4)-1)*(i-(t+4))/2)%p)%p;
if(t+5<=i-1) f[i][j]=(f[i][j]+c[n-(t+5)][i-(t+5)]*sum[(t+5)][j-1]%p*qpow(k-j+1,(i-2+(t+5)-1)*(i-(t+5))/2)%p)%p;
if(t+6<=i-1) f[i][j]=(f[i][j]+c[n-(t+6)][i-(t+6)]*sum[(t+6)][j-1]%p*qpow(k-j+1,(i-2+(t+6)-1)*(i-(t+6))/2)%p)%p;
if(t+7<=i-1) f[i][j]=(f[i][j]+c[n-(t+7)][i-(t+7)]*sum[(t+7)][j-1]%p*qpow(k-j+1,(i-2+(t+7)-1)*(i-(t+7))/2)%p)%p;
if(t+8<=i-1) f[i][j]=(f[i][j]+c[n-(t+8)][i-(t+8)]*sum[(t+8)][j-1]%p*qpow(k-j+1,(i-2+(t+8)-1)*(i-(t+8))/2)%p)%p;
if(t+9<=i-1) f[i][j]=(f[i][j]+c[n-(t+9)][i-(t+9)]*sum[(t+9)][j-1]%p*qpow(k-j+1,(i-2+(t+9)-1)*(i-(t+9))/2)%p)%p;
}
sum[i][j]=(sum[i][j-1]+f[i][j])%p;
}
}
int ans=0;
for(register int i=1; i<=k; ++i) {
ans=(ans+f[n][i])%p;
}
write(ans);
return 0;
}