Submission #992337

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Source Code Expand

#include<cstdio>
#include<algorithm>

using namespace std;

const long long inf = 1e15;

long long mul(long long a, long long b){
	if(a == 0 || b == 0) return 0;
	long long tmp = inf / a;
	if(tmp <= b) return inf;
	long long x = a * b;
	return min(x, inf);
}

long long ex(long long a, int e){
	if(e == 0) return 1;
	long long tmp = ex(a, e / 2);
	tmp = mul(tmp, tmp);
	if(e % 2 == 1) tmp = mul(tmp, a);
	return tmp;
}

long long N, A;

long long solve(){
	long long ans = N;
	for(int n = 2; n <= 40; ++n){
		long long lb = 1, ub = N;
		while(ub - lb > 1){
			long long mid = (ub + lb) / 2;
			long long val = ex(mid, n);
			if(val <= N) lb = mid;
			else ub = mid;
		}
		if(lb == 1) continue;
		else{
			long long x = lb, y = lb + 1;
			int lb = -1, ub = n;
			while(ub - lb > 1){
				int mid = (ub + lb) / 2;
				long long val = mul(ex(x, n - mid), ex(y, mid));
				if(val >= N){
					ub = mid;
				}else{
					lb = mid;
				}
			}
			long long tmp = x * (n - ub) + y * ub + A * (n - 1);
			ans = min(ans, tmp);
		}
	}
	return ans;
}

int main(){
	scanf("%lld%lld", &N, &A);
	long long ans = solve();
	printf("%lld\n", ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:57:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld", &N, &A);
                           ^

Judge Result