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MaximumSwaps.java
71 lines (59 loc) · 1.59 KB
/
MaximumSwaps.java
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// https://leetcode.com/problems/maximum-swap
class Solution {
public int maximumSwap(int num) {
int[] arr = toArray(num);
int breakPoint = isMaxAlready(arr);
if (breakPoint < 0) {
return num;
}
int[] max = maxDigit(arr, breakPoint);
for (int i = 0; i < max[1]; i++) {
if (arr[i] != max[0] && i != max[1] && arr[i] < max[0]) {
int t = arr[i];
arr[i] = max[0];
arr[max[1]] = t;
break;
}
}
return toNum(arr);
}
int[] toArray(int num) {
int len = ((int) Math.log10(num)) + 1;
int[] res = new int[len];
for (int i = len - 1; i >= 0; i--) {
res[i] = num % 10;
num /= 10;
}
return res;
}
int isMaxAlready(int[] arr) {
for (int i = 1; i < arr.length; i++) {
if (arr[i] > arr[i - 1]) {
return i - 1;
}
}
return -1;
}
int[] maxDigit(int[] arr, int start) {
int max = 0, index = -1, i = 0;
for (int x: arr) {
if (i < start) {
i++;
continue;
}
if (x >= max) {
max = x;
index = i;
}
i++;
}
return new int[] {max, index};
}
int toNum(int[] arr) {
int res = 0;
for (int x: arr) {
res = res * 10 + x;
}
return res;
}
}