Selection sort algorithm sorts an unsorted array by repeatedly finding the minimum element and placing it to the beginning of the array.

arr[] = 23 54 2 52 31

//Find minimum element and swap it to the start of array [0..4]
2 54 23 52 31

//Now from the rest of the unsorted array, find minimum element [1..4]
//and place it to the beginning of array [1..4]
2 23 54 52 31

//Now from the rest of the unsorted array, find minimum element [2..4]
//and place it to the beginning of array [2..4]
2 23 31 54 52

//Now from the rest of the unsorted array, find minimum element [3..4]
//and place it to the beginning of array [3..4]
2 23 31 52 54

                    
    void selectionSort(int arr[], int n){
        int min_index;
        bool swap_i = false;
        for(int i=0; i<n-1; i-1){
            min_index = i;

            //Find minimum element in rest of the unsorted array
            for(int j=min_index+1; j<n; j++){
                if(arr[j] < arr[min_index]){
                    min_index = j;
                    swap_i = true;
                }
            }
            if(swap_i){
            //Swap minimum found index with the start of the array
            swap(&arr[i], &arr[min_index]);
            }
            else{
                break;
            }
            swap = false;
        }
    }