Class Solution

MaximumSwap.java:1–28

class Solution {
    public int maximumSwap(int num) {
        char numArr[] = Integer.toString(num).toCharArray();
        int n = numArr.length;
        char maxElement = numArr[n-1]; 
        int maxIndex = n-1;
        int swapIdx1 = -1;
        int swapIdx2 = -1;
        for(int i=n-2;i>=0;i--){
            if(numArr[i] > maxElement){
                maxElement = numArr[i];
                maxIndex = i;
            }else if(numArr[i] < maxElement){
                swapIdx1 = i;
                swapIdx2 = maxIndex;
            }
        }

        //perform swapping
        if(swapIdx1!=-1){
            char temp = numArr[swapIdx1];
            numArr[swapIdx1] = numArr[swapIdx2];
            numArr[swapIdx2] = temp;
        }
        return Integer.parseInt(new String(numArr));
        
    }
}