Submission #38636447

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define op(x) ((x&1)?x+1:x-1)
#define odd(x) ((x)&1)
#define even(x) (!odd((x)))
#define lc(x) (x<<1)
#define rc(x) (lc(x)|1)
#define lowbit(x) (x&-x)
#define mp(x,y) make_pair(x,y)
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
using namespace std;
const ll MAXN=210,LIM=200,mod=998244353;
void add(ll&x,ll y){x=(x+y)%mod;}
void sub(ll&x,ll y){x=(x-y+mod)%mod;}
ll mypow(ll a,ll n){
    if(!n)return 1;
    ll tmp=mypow(a,n/2);tmp=tmp*tmp%mod;
    if(n&1)tmp=tmp*a%mod;return tmp;
}
ll myinv(ll a){return mypow(a,mod-2);}
ll P(ll x){return (x%2)?(mod-1):(1);}
//
ll n,m,x;
ll c1[MAXN][MAXN],c2[MAXN][MAXN],fact[MAXN],factinv[MAXN],pw[MAXN];
ll f[MAXN]; //f(i) : i个变量xor=x的方案数
ll g[MAXN]; //g(i) : i个不同变量xor=x的方案数
ll h[MAXN];

ll dp[MAXN][MAXN],dp2[MAXN][MAXN];

ll C(int x,int y){
    if(x<=LIM)return c1[x][y];
    if(y<0)return 0;
    ll res=1;
    rep(i,1,y)res=res*((x-i+1)%mod)%mod;
    return res*factinv[y]%mod;
}
ll HC(int x,int mode){
    if(x)return pw[x-1];
    else return !mode;
}
ll H(int x){return P(x-1)*fact[x-1]%mod;}

void pre_solve(ll n){
    ll& ans=f[n];
    memset(dp,0,sizeof dp);
    dp[31][0]=1;
    per(i,30,0)rep(j,0,n)if(dp[i+1][j]){
        ll ways=dp[i+1][j];
        int bit=(x>>i&1);
        if(m>>i&1){
            rep(k,0,n-j){
                add(dp[i][n-k],ways*C(n-j,k)%mod*HC(j,odd(k^bit))%mod);
            }
        }else{
            rep(k,0,j)if(even(k^bit)){
                add(dp[i][j],ways*C(j,k)%mod);
            }
        }
    }
    ans=dp[0][n];
}
void solve_g(){
    memset(dp,0,sizeof dp);
    dp[0][0]=dp2[0][0]=1;
    rep(i,0,n-1)rep(j,0,n-1){
        ll ways=dp[i][j],ways2=dp2[i][j];
        rep(k,1,n-j)if(odd(k)){
            add(dp[i+1][j+k],ways*factinv[k]%mod*H(k)%mod);
        }else{
            add(dp2[i+1][j+k],ways2*factinv[k]%mod*H(k)%mod);
        }
    }

    rep(i,0,n)rep(j,0,n)add(h[j],dp2[i][j]*factinv[i]%mod*mypow(m,i)%mod);
    

    rep(i,1,n)rep(j,0,i)rep(k,0,n){
        ll ways=dp[j][k]*h[i-k]%mod;
      
        if(!ways)continue;
        ways=ways*fact[i]%mod*factinv[j]%mod;

        add(g[i],ways*f[j]%mod);
    }
    rep(i,1,n)g[i]=g[i]*factinv[i]%mod;
}
int main(){

    pw[0]=fact[0]=1;rep(i,1,LIM)fact[i]=fact[i-1]*i%mod,pw[i]=pw[i-1]*2%mod;
    factinv[LIM]=myinv(fact[LIM]);per(i,LIM-1,0)factinv[i]=factinv[i+1]*(i+1)%mod;

    c1[0][0]=1;
    rep(i,1,LIM){
        c1[i][0]=1;
        rep(j,1,i)c1[i][j]=c1[i-1][j],add(c1[i][j],c1[i-1][j-1]);
    }
    cin>>n>>m>>x;m++;

    //
    f[0]=g[0]=(x==0);
    rep(i,1,n){
        pre_solve(i);
    }
    solve_g();

    ll ans=0;

    rep(i,0,n/2){
        int rest=n-2*i;
        ll ways=g[rest];
        ways=ways*C(m+i-1,i)%mod;

        add(ans,ways);
    }
    cout<<ans<<"\n";
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘ll mypow(ll, ll)’:
./Main.cpp:21:5: warning: this ‘if’ clause does not guard... [-Wmisleading-indentation]
   21 |     if(n&1)tmp=tmp*a%mod;return tmp;
      |     ^~
./Main.cpp:21:26: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
   21 |     if(n&1)tmp=tmp*a%mod;return tmp;
      |                          ^~~~~~

Judge Result