73. Numbers that occur more than half of the time in the array

Title description

The number of occurrences of a number in the array exceeds half of the length of the array. Please find out this number. For example, enter an array {1,2,3,2,2,2,5,4,2} with a length of 9. Since the number 2 appears 5 times in the array, which is more than half the length of the array, 2 is output. If it does not exist, output 0.

Example 1

enter

[1,2,3,2,2,2,5,4,2]

return value

2

Idea :
Compare the number count+1 that appears for the first time with the subsequent numbers. If it is equal, then +1, otherwise -1,
and finally check whether it exceeds half of the length.

Code implementation :

public class Solution {
    public int MoreThanHalfNum_Solution(int [] array) {
        int count = 0;
        int flag = 0;
        for (int num : array) {
            if (count == 0) {
                flag = num;
            }
            count += (flag == num) ? 1 : -1;
        }
        count = 0;
        for (int num : array) {
            if (num == flag) {
                count++;
            }
        }
        return (count * 2 > array.length) ? flag : 0;
    }
}