competitive-programming/solved-lightOj/1067.cpp at master · the-redback/competitive-programming · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
/**
 *                                   ____
 *       ____ ___  ____ ________  __/ __/
 *      / __ `__ \/ __ `/ ___/ / / / /_
 *     / / / / / / /_/ / /  / /_/ / __/
 *    /_/ /_/ /_/\__,_/_/   \__,_/_/
 *
 *    @link : https://the-redback.com
 */
#include <bits/stdc++.h>
using namespace std;
#define inf       HUGE_VAL
#define mem(a, b) memset(a, b, sizeof(a))
#define mod       1000003
#define NN        1000001
int fact[NN + 7];
int go(int n, int q) {
    if (q == 1) return n % mod;
    if (q % 2)
        return ((long long)(n % mod) * go(n, q - 1)) % mod;
    else {
        int k = go(n, q / 2);
        return ((long long)k * k) % mod;
    }
}

int main() {
    int n, k, l, r, i;
    int tc, t = 1;
    fact[0] = 1;
    for (i = 1; i < NN; i++) fact[i] = ((long long)i * fact[i - 1]) % 1000003;
    scanf("%d", &tc);
    while (tc--) {
        scanf("%d%d", &n, &k);
        r = ((long long)fact[k] * fact[n - k]) % mod;
        int inmod = go(r, mod - 2) % mod;
        int ans = ((long long)fact[n] * inmod) % mod;
        printf("Case %d: %d\n", t++, ans);
    }
    return 0;
}