[BOJ] 14888번 연산자 끼워넣기

1. problem : 

https://www.acmicpc.net/problem/14888

 

 

2. solution 1 :

#include <bits/stdc++.h>
using namespace std;
int n;
int nums[102];
int cal[4]; // + - x / ; 
int mxans = -0x7f7f7f7f, mnans = 0x7f7f7f7f;
int temp_sum;

void backTrack(int k) {
	if (k == n) {
		mxans = max(mxans, temp_sum); 
		mnans = min(mnans, temp_sum);
		return;
	}
	if (k == 1) temp_sum = nums[0];
	for (int i = 0; i < 4; i++) {
		if (cal[i] > 0) {
			int dormamu = temp_sum;
			if (i == 0) {
				temp_sum += nums[k];
			}
			else if (i == 1) {
				temp_sum -= nums[k];
			}
			else if (i == 2) {
				temp_sum *= nums[k];
			}
			else {
				if (temp_sum < 0) {
					temp_sum = -(-temp_sum / nums[k]);
				}
				else temp_sum /= nums[k];
			}
			cal[i] -= 1;
			backTrack(k + 1);
			temp_sum = dormamu;
			cal[i] += 1;
		}
		
	}
	
}

int main(void) {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n; 
	for (int i = 0; i < n; i++) cin >> nums[i]; 
	for (int i = 0; i < 4; i++) cin >> cal[i]; 
	
	backTrack(1); 
	cout << mxans << '\n';
	cout << mnans << '\n';

}

 

3. solution 2 :

// Authored by : SciEm
// Co-authored by : -
// http://boj.kr/d1e716682fbe499881cd32ec1c235f7e
#include <bits/stdc++.h>
using namespace std;

int nums[12];
int ops[12];  // ops[0]은 항상 더하기
int n;
int mn = 0x7f7f7f7f, mx = -0x7f7f7f7f;

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  cin >> n;
  for (int i = 0; i < n; i++)
    cin >> nums[i];
  for (int op = 0, idx = 1; op < 4; op++) {
    int x; cin >> x;
    while (x--)
      ops[idx++] = op;
  }

  do {
    int res = 0;
    for (int i = 0; i < n; i++) {
      if (ops[i] == 0) res += nums[i];
      else if (ops[i] == 1) res -= nums[i];
      else if (ops[i] == 2) res *= nums[i];
      else res /= nums[i];
    }
    mx = max(mx, res);
    mn = min(mn, res);
  } while (next_permutation(ops + 1, ops + n));
  cout << mx << '\n' << mn;
}

source code 출처 : https://github.com/encrypted-def/basic-algo-lecture/blob/master/0x0D/solutions/14888_1.cpp

basic-algo-lecture/0x0D/solutions/14888_1.cpp at master · encrypted-def/basic-algo-lecture