Submission #243205

#	Time	Username	Problem	Language	Result	Execution time	Memory
243205		pavel	Tents (JOI18_tents)	C++14	100 / 100	289 ms	35960 KiB

tents

#include <cstdio>


using namespace std;

const int MAXD = 3003;

int dp[MAXD][MAXD];

typedef long long ll;
const int MOD = 1000000007;

int ADD(ll a, ll b){
    return (a+b)%MOD;
}
int SUB(ll a, ll b){
    return (a+MOD-b)%MOD;
}
int MUL(ll a, ll b){
    return (a*b)%MOD;
}

int solve(int h, int w){
    int& r = dp[h][w];
    if(r == -1){
        if(h == 0 || w == 0){
            r = 1;
        }else{
            r = ADD(solve(h, w-1), MUL(4*h, solve(h-1, w-1)));
            if(h >= 2) r = ADD(r, MUL(h*(h-1)/2, solve(h - 2, w - 1)));
            if(w >= 2) r = ADD(r, MUL(h*(w-1), solve(h - 1, w - 2)));
        }
    }
    return r;
}

int main(){
    for(int i=0;i<MAXD;++i) for(int j=0;j<MAXD;++j) dp[i][j] = -1;
    int h,w;
    scanf("%d%d", &h, &w);
    printf("%d\n", SUB(solve(h, w), 1));
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:40:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &h, &w);
     ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 48 / 48
• Subtask 2: 52 / 52