algorithm/Week_01/id_121/LeetCode_905_121.java at master · isnotnull/algorithm · GitHub

37 lines (35 loc) · 1.01 KB

class Solution {

public int[] sortArrayByParity(int[] A) {

if(A == null || A.length < 1 || A.length > 5000){

return null;

}

int head = 0;

int tail = A.length - 1;

while(head >=0 && tail>= 0 && head < A.length && tail < A.length && head < tail){

if(!isOdd(A[head]) && isOdd(A[tail])){

head ++;

tail --;

}else if(isOdd(A[head]) && !isOdd(A[tail])){

swap(A,head,tail);

head ++;

tail --;

}else if(isOdd(A[head]) && isOdd(A[tail])){

tail --;

}else if(!isOdd(A[head]) && !isOdd(A[tail])){

head ++;

}

return A;

}

public void swap(int[] arr,int head,int tail){

int tmp = arr[head];

arr[head] = arr[tail];

arr[tail] = tmp;

}

public boolean isOdd(int a){

if(a%2 == 1){ //是奇数

return true;

}

return false;

}

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