Submission #223121

#	Time	Username	Problem	Language	Result	Execution time	Memory
223121		patrikpavic2	Asceticism (JOI18_asceticism)	C++17	100 / 100	42 ms	1280 KiB

asceticism

#include <cstdio>
#include <cstring>
#include <vector>

#define X first
#define Y second
#define PB push_back

using namespace std;

typedef long long ll;
typedef pair < int , int > pii;
typedef vector < int > vi;

const int N = 1e5 + 500;
const int MOD = 1e9 + 7;

inline int add(int A,int B){
	if(A + B >= MOD) return A + B - MOD;
	return A + B;
}

inline int mul(int A,int B){
	return (ll)A * B % MOD;
}

inline int sub(int A,int B){
	if(A - B < 0) return A - B + MOD;
	return A - B;
}

inline int pot(int A,int B){
	int ret = 1, bas = A;
	for(;B;B >>= 1){
		if(B&1) ret = mul(ret, bas);
		bas = mul(bas, bas);
	}
	return ret;
}

int fak[N], inv[N], n, k;

void precompute(){
	fak[0] = 1; inv[0] = 1;
	for(int i = 1;i < N;i++){
		fak[i] = mul(fak[i - 1], i);
		inv[i] = pot(fak[i], MOD -2);
	}
}

int choose(int n,int k){
	return mul(fak[n], mul(inv[k], inv[n - k]));
}

int main(){
	precompute();
	scanf("%d%d", &n, &k);
	int ret = 0;
	for(int i = 0;i <= k;i++){
		ret = add(ret, mul(pot(MOD - 1, i), mul(choose(n + 1, i), pot(k - i, n))));
	}
	printf("%d\n", ret);
	return 0;
}

Compilation message (stderr)

asceticism.cpp: In function 'int main()':
asceticism.cpp:57:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &k);
  ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 51 / 51