선택정렬 구현 연습

#include <iostream>
using namespace std;

void swap(int * arr,int a,int b){
    int temp = arr[a];
    arr[a] = arr[b];
    arr[b] = temp;
}

int findindex(int* arr,int left,int right){
    int minindex = left;
    for(int i=minindex+1; i<right; i++){
        if(arr[i]<arr[minindex])
            minindex = i;
    }
    return minindex;
}

//배열 스캔 후 최소값 찾은다음에 맨앞 이랑 교환, 맨앞은 점점 증가되다가 마지막까지감
int selectionsort(int* arr,int left,int right){
    for(int i=left; i<right; i++){
        int index = findindex(arr,i,right);
        swap(arr,i,index);
    }
}

int main(){
    int arr[] = {2,2,4,5,1,55,2,4,5,29,4,0,-1};
    selectionsort(arr,0,13);
    for(int k : arr)
        cout<<k<<" ";
    cout<<endl;

}

좀 더 간략화 된 방법

#include <iostream>
using namespace std;

void selectionsort(int* arr,int left,int right){
    for(int i=left; i<right; i++){
        int minindex = i;
        for(int j=i+1; j<right; j++){
            if(arr[minindex] > arr[j])
                minindex = j;
        }
        //swap minindex and i
        int temp = arr[minindex];
        arr[minindex] = arr[i];
        arr[i] = temp;
    }
}

int main(){
    int arr[] = {2,2,4,5,1,55,2,4,5,29,4,0,-1};
    selectionsort(arr,0,13);
    for(int k : arr)
        cout<<k<<" ";
    cout<<endl;

}