Sword finger offer 21 Adjust array order so that odd numbers precede even numbers

The finger of the sword Offer 21. Adjust the array order so that the odd Numbers precede the even Numbers

subject

Code

#include <iostream>
#include <vector>
using namespace std;

//  Method 1 ： Time limit exceeded  
vector<int> exchange1(vector<int>& nums) {
    
	int n = nums.size();
	if(n == 0 || n == 1){
    
		return nums;
	}
	for(int i = 0; i < n - 1; i++){
    
		if(nums[i] % 2 == 1){
    
			continue;
		}
		for(int j = i + 1; j < n; j++){
    
			if(nums[j] % 2 == 1){
    
				int temp = nums[i];
				nums[i] = nums[j];
				nums[j] = temp;
				break;
			}
		}
	}
	return nums;
}

//  Method 2 ： Using the array , Odd number from to save , Even numbers are saved from back to front  
vector<int> exchange(vector<int>& nums) {
    
	int n = nums.size();
	if(n == 0 || n == 1){
    
		return nums;
	}
	vector<int> res (n);
	int j = 0, k = n - 1;
	for(int i = 0; i < n; i++){
    
		if(nums[i] % 2 == 1){
    
			res[j++] = nums[i];
		}else{
    
			res[k--] = nums[i];
		}
	}
	return res;
}

int main(){
    
	int n;
	cin>>n;
	vector<int> nums(n);
	vector<int> res;
	for(int i = 0; i < n; i++){
    
		cin>>nums[i];
	}
	res = exchange(nums);
	for(int i = 0; i < res.size(); i++){
    
		cout<<res[i]<<" ";
	}
	return 0;
}