剑指offer-题29：数组中出现次数超过一半的数字

题目描述

数组中有一个数字出现的次数超过数组长度的一半，请找出这个数字。例如输入一个长度为9的数组{1,2,3,2,2,2,5,4,2}。由于数字2在数组中出现了5次，超过数组长度的一半，因此输出2。如果不存在则输出0。

实验平台：牛客网

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解决思路：

java:

public class Solution {
    public int MoreThanHalfNum_Solution(int [] array) {
        int arrayLen = array.length;
        if (array == null || arrayLen == 0) {
            return 0;
        } else {
            int times = 1;
            int totleTimes = 0; // 某个数字出现的总次数
            int num = array[0];
            for (int i = 1; i < arrayLen; i++) {
                if (times == 0) {
                    num = array[i];
                    times = 1;
                } else if (array[i] == num) {
                    times++;
                } else {
                    times--;
                }
            }
            for (int j = 0; j < arrayLen; j++) {
                if (array[j] == num) {
                    totleTimes++;
                }
            }
            if (totleTimes > arrayLen / 2) {
                return num;
            } else {
                return 0;
            }
        }
    }
}

python:

# -*- coding:utf-8 -*-
class Solution:
    def MoreThanHalfNum_Solution(self, numbers):
        # write code here
        list_len = len(numbers)
        if numbers is None or list_len == 0:
            return 0
        else:
            times = 1
            num = numbers[0]
            for i in range(1, list_len):
                if times == 0:
                    num = numbers[i]
                    times = 1
                elif numbers[i] == num:
                    times += 1
                else:
                    times -= 1
            totle_num = numbers.count(num)
            if totle_num > list_len/2:
                return num
            else:
                return 0