Algorithm

c++로 stringTokenizer

string s = "";

vector<string> split(string input, char delimiter) {
    vector<string> answer;
    stringstream ss(input);
    string temp;

    while (getline(ss, temp, delimiter)) {
        if (temp == "" || temp.empty()) {
            continue;
        }
        answer.push_back(temp);
    }

    return answer;
}

python으로 순열

arr = [1, 2, 3, 4, 5]

n = 5
arr = []
for i in range(1, n + 1):
    arr.append(i)
visited = [0] * n


def permutation(candidate, chosen, n):
    if len(chosen) == n:
        for i in chosen:
            print(i, end=' ')
        print()
        return

    for i in range(len(candidate)):
        if not visited[i]:
            chosen.append(candidate[i])
            visited[i] = 1
            permutation(candidate, chosen, n)
            visited[i] = 0
            chosen.pop()


permutation(arr, [], n)

python으로 조합

def combinations(arr, n):
    result =[] 

    if n == 0: 
        return [[]]

    for i in range(0, len(arr)): 
        elem = arr[i] 
        rest_arr = arr[i + 1:] 
        for comb in combinations(rest_arr, n-1): 
            result.append([elem]+comb) 
              
    return result

next_permutation을 이용한 조합

vector<int> v{1,2,3,4}; // 조합 출력할 원소들
vector<int> c{0,0,1,1}; // 4개중 2개를 뽑을 벡터리스트 (순서 중요)

do{
        for(int i =0; i<v.size();i++) {
                if(c[i]==1)cout<<v[i]<<' '; 
        }
        cout<<endl; 
}while(next_permutation(c.begin(),c.end()));

//출력결과
3 4 
2 4 
2 3 
1 4 
1 3 
1 2 

// prev_permu..를 이용한 조합
vector<int> v{1,2,3,4};
vector<int> c{1,1,0,0}; // 4개중 2개를 뽑을 벡터리스트 (순서 중요)

do{
      for(int i =0; i<v.size();i++) {
              if(c[i]==1)cout<<v[i]<<' '; 
      }
      cout<<endl; 
}while(prev_permutation(c.begin(),c.end()));

//출력결과
1 2 
1 3 
1 4 
2 3 
2 4 
3 4 

nPr

#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

vector<int> v;

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

	vector<int> v = { 1, 2, 3, 4, 5 };

	int n = v.size();  // 5
	int r = 2;

	do
	{
		for (int i = 0; i < r; i++)
		{
			cout << v[i] << " ";
		}
		cout << '\n';
		reverse(v.begin() + r, v.end());

	} while (next_permutation(v.begin(), v.end()));
}