【Codeforces】1213A - Chips Moving

Problem Description：

You are given n chips on a number line. The i-th chip is placed at the integer coordinate 

. Some chips can have equal coordinates.

You can perform each of the two following types of moves any (possibly, zero) number of times on any chip:

• Move the chip i by 2 to the left or 2 to the right for free (i.e. replace the current coordinate  with  or with );
• move the chip i by 1 to the left or 1 to the right and pay one coin for this move (i.e. replace the current coordinate  with  or with ).

Note that it's allowed to move chips to any integer coordinate, including negative and zero.

Your task is to find the minimum total number of coins required to move all n chips to the same coordinate (i.e. all 

 should be equal after some sequence of moves).

Input Specification:

The first line of the input contains one integer n (1 ≤ n ≤ 100) — the number of chips.

The second line of the input contains n integers

,

,…,

 (1 ≤

 ≤ 109), where 

 is the coordinate of the i-th chip.

Output Specification:

Print one integer — the minimum total number of coins required to move all n chips to the same coordinate.

Sample Input1:

3
1 2 3

Sample Output1:

1

Sample Input2:

5
2 2 2 3 3

Sample Output2:

2

解题思路：

这道题目的大意说白了就是输出奇偶数中个数较少的那个。判断奇偶性的时候用n&1或者n%2都行，这俩个是等价的。

AC代码：

#include <bits/stdc++.h>
using namespace std;
#define Up(i,a,b) for(int i = a; i <= b; i++)

int main()
{
    ios::sync_with_stdio(false);
    int n, odd = 0, even = 0;
    cin >> n;
    Up(i,1,n)
    {
        int _;
        cin >> _;
        (_%2 ? odd++ : even++);  //判断奇偶性，并记录奇偶数的个数
    }
    cout << min(odd,even) << endl;
    return 0;
}