Submission #35227

#	Time	Username	Problem	Language	Result	Execution time	Memory
35227		wan2000	마스코트 (JOI13_mascots)	C++14	0 / 100	0 ms	1840 KiB

mascots

#include <bits/stdc++.h>

using namespace std;

template<typename T> inline void read(T &x){
    x = 0; char ch;
    while(!isdigit(ch=getchar()));
    do{x=10*x+ch-'0';}while(isdigit(ch=getchar()));
}
template<typename T> inline void write(T x){
    if(x<=9){ putchar(x+'0'); return;}
    write(x/10); putchar(x%10+'0');
}
template<typename T> inline void writeln(T x){
    write(x); putchar('\n');
}

typedef long long ll;

const int N = 3333;
const ll MOD = 1e9+7;

int row, col, n;
ll F[N][N], Fac[N*N], Finv[N*N], res;

ll power(ll a, int x){
    if(x==1) return a;
    ll tmp = power(a,x>>1);
    tmp = (tmp*tmp)%MOD;
    if(x%2) tmp = (tmp*a)%MOD;
    return tmp;
}

void init(){
    Fac[0] = 1;
    for(int i = 1; i <= row*col; i++) Fac[i] = (Fac[i-1]*(ll)i)%MOD;
    Finv[0] = 1;
    for(int i = 1; i <= row*col; i++){
        ll inv = power((ll)i,MOD-2);
        Finv[i] = (Finv[i-1]*inv)%MOD;
    }
}

ll BC(int k, int n){
    return ((Fac[n]*Finv[k])%MOD*Finv[n-k])%MOD;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    read(row); read(col);
    init();
    read(n);
    int u = N, v = N, p = 0, q = 0;
    for(int i = 1; i <= n; i++){
        int x, y;
        read(x); read(y);
        u = min(u,x);
        v = min(v,y);
        p = max(p,x);
        q = max(q,x);
    }
    int x = p-u+1;
    int y = q-v+1;
    ll need = Fac[x*y-n];
    F[row][col] = 1;
    for(int i = row; i >= x; i--){
        for(int j = col; j >= y; j--){
            if(i==row&&j==col) continue;
            F[i][j] = (F[i+1][j]*Fac[j]+F[i][j+1]*Fac[i])%MOD;
        }
    }
    res = F[x][y]*BC(u-1,row-x)*BC(v-1,col-y)*need;
    writeln(res);
    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 30
• Subtask 3: 0 / 60