답안 #212362

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
212362 2020-03-22T18:36:11 Z bash Asceticism (JOI18_asceticism) C++17
100 / 100
108 ms 1152 KB
/**
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*/
#include <cstring>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <queue>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cassert>
 
#define F first
#define S second
#define endl '\n'
#define deb(x) cout<<#x<<' '<<x<<endl;
#define pb push_back
 using namespace __gnu_pbds;
using namespace std;

typedef tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
/*
#ifdef IZI_KATKA
#define int __int64_t
#else
#define int __int64
#endif
*/
const long long MOD = 1e9 + 7;
const long long MAXN = 1e6 + 1;

typedef long long ll;

#define pii pair<int,int>
 
long long readInt() {
    bool minus1 = false;
    long long result = 0;
    char ch;
    ch = getchar();
    while (true) {
        if (ch == '-') break;
        if (ch >= '0' && ch <= '9') break;
        ch = getchar();
    }
    if (ch == '-') minus1 = true; else result = ch-'0';
    while (true) {
        ch = getchar();
        if (ch < '0' || ch > '9') break;
        result = result*10 + (ch - '0');
    }
    if (minus1)
        return -result;
    else
        return result;
}
#define int ll

int f[MAXN];

long long bin_pow(long long base, long long p) {
    if (p == 1) {
        return base;
    }

    if (p % 2 == 0) {
        long long t = bin_pow(base, p / 2);
        return t * t % MOD;
    } else {
        return bin_pow(base, p - 1) * base % MOD;
    }
}

long long inverse_element(long long x) {
    return bin_pow(x, MOD - 2);
}

//(a / b) mod m
long long divide(long long a, long long b) {
    return a * inverse_element(b) % MOD;
}

int cnk(int n, int k) {
	return divide(f[n], (f[n - k] * f[k]) % MOD);
}

int solve(int n, int k) {
	int sum = 0;
	for (int i = 0; i <= k; i++) {
		int res = cnk(n, i) * bin_pow(k - i, n);
		res %= MOD;
		if (i & 1) {
			res = MOD - res;
		}	
		sum += res;
		sum %= MOD;
	}
	return sum;
}

main() {
	#ifdef IZI_KATKA
	assert(freopen("input", "r", stdin));
    assert(freopen("output", "w", stdout));
    #endif
    int n = readInt(), k = readInt();
	f[0] = 1;    
    for (int i = 1; i <= n; i++) {
		f[i] = (f[i - 1] * i) % MOD;    	
    }
	int ans = solve(n, k);
	ans += ((MOD - solve(n, k - 1)) % MOD);
	ans %= MOD;
	cout << ans << endl;
	return 0;
}

Compilation message

asceticism.cpp:122:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 256 KB Output is correct
2 Correct 5 ms 256 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 256 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 4 ms 256 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 256 KB Output is correct
9 Correct 5 ms 256 KB Output is correct
10 Correct 5 ms 256 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 256 KB Output is correct
2 Correct 5 ms 256 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 256 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 4 ms 256 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 256 KB Output is correct
9 Correct 5 ms 256 KB Output is correct
10 Correct 5 ms 256 KB Output is correct
11 Correct 5 ms 384 KB Output is correct
12 Correct 4 ms 384 KB Output is correct
13 Correct 4 ms 384 KB Output is correct
14 Correct 5 ms 384 KB Output is correct
15 Correct 5 ms 384 KB Output is correct
16 Correct 5 ms 384 KB Output is correct
17 Correct 5 ms 384 KB Output is correct
18 Correct 5 ms 384 KB Output is correct
19 Correct 5 ms 384 KB Output is correct
20 Correct 5 ms 256 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 256 KB Output is correct
2 Correct 5 ms 256 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 256 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 4 ms 256 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 256 KB Output is correct
9 Correct 5 ms 256 KB Output is correct
10 Correct 5 ms 256 KB Output is correct
11 Correct 5 ms 384 KB Output is correct
12 Correct 4 ms 384 KB Output is correct
13 Correct 4 ms 384 KB Output is correct
14 Correct 5 ms 384 KB Output is correct
15 Correct 5 ms 384 KB Output is correct
16 Correct 5 ms 384 KB Output is correct
17 Correct 5 ms 384 KB Output is correct
18 Correct 5 ms 384 KB Output is correct
19 Correct 5 ms 384 KB Output is correct
20 Correct 5 ms 256 KB Output is correct
21 Correct 4 ms 384 KB Output is correct
22 Correct 5 ms 384 KB Output is correct
23 Correct 5 ms 384 KB Output is correct
24 Correct 5 ms 384 KB Output is correct
25 Correct 9 ms 512 KB Output is correct
26 Correct 6 ms 384 KB Output is correct
27 Correct 7 ms 384 KB Output is correct
28 Correct 5 ms 384 KB Output is correct
29 Correct 5 ms 384 KB Output is correct
30 Correct 7 ms 384 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 256 KB Output is correct
2 Correct 5 ms 256 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 256 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 4 ms 256 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 256 KB Output is correct
9 Correct 5 ms 256 KB Output is correct
10 Correct 5 ms 256 KB Output is correct
11 Correct 5 ms 384 KB Output is correct
12 Correct 4 ms 384 KB Output is correct
13 Correct 4 ms 384 KB Output is correct
14 Correct 5 ms 384 KB Output is correct
15 Correct 5 ms 384 KB Output is correct
16 Correct 5 ms 384 KB Output is correct
17 Correct 5 ms 384 KB Output is correct
18 Correct 5 ms 384 KB Output is correct
19 Correct 5 ms 384 KB Output is correct
20 Correct 5 ms 256 KB Output is correct
21 Correct 4 ms 384 KB Output is correct
22 Correct 5 ms 384 KB Output is correct
23 Correct 5 ms 384 KB Output is correct
24 Correct 5 ms 384 KB Output is correct
25 Correct 9 ms 512 KB Output is correct
26 Correct 6 ms 384 KB Output is correct
27 Correct 7 ms 384 KB Output is correct
28 Correct 5 ms 384 KB Output is correct
29 Correct 5 ms 384 KB Output is correct
30 Correct 7 ms 384 KB Output is correct
31 Correct 5 ms 1152 KB Output is correct
32 Correct 5 ms 1152 KB Output is correct
33 Correct 9 ms 1152 KB Output is correct
34 Correct 20 ms 1152 KB Output is correct
35 Correct 88 ms 1152 KB Output is correct
36 Correct 98 ms 1152 KB Output is correct
37 Correct 108 ms 1152 KB Output is correct
38 Correct 17 ms 512 KB Output is correct
39 Correct 37 ms 1016 KB Output is correct
40 Correct 48 ms 1152 KB Output is correct