[BOJ/백준][Bronze1] 21760 : 야구 시즌 (C++)

https://www.acmicpc.net/problem/21760

21760번: 야구 시즌

 

 

[난이도] Bronze1
[유형] 수학

[풀이]
N,M,k,D가 모두 주어지고 A=k*B 이기 때문에 식을 잘 세워보면
미지수는 B밖에 남지 않는 다는 것을 알 수 있습니다.
식을 잘 정리한 뒤 반복문을 이용해 B가 조건을 만족하지 않을 때까지 증가시켜가며 B의 최적값을 찾아주면 됩니다.

 

 

#include <algorithm>
using namespace std;
using ll = long long;
int T;
ll N,M,k,D;
int main(){
    scanf("%d",&T);
    while(T--){
        scanf("%lld%lld%lld%lld",&N,&M,&k,&D);
        ll B=0;
        while(N*M*B*(k*(M-1)+M*(N-1))<=2*D) B++;
        if(B<=1) {
            puts("-1");
            continue;
        }
        ll a=N*M*(B-1)*(k*(M-1)+M*(N-1));
        printf("%lld\n",a/2);
    }
}

 

https://github.com/has2/Problem-Solving/blob/master/boj-solved.ac/Bronze1/21760.cpp