常用数据结构之位操作

/*
     * 比较两个数字bit位不同的个数
     */
    int numberOfDifferentBits(int A, int B) {
        int diff = A ^ B;
        int count = 0;
        while (diff > 0) {
            count += diff & 0x1;
            diff = diff >> 1;
        }
        return count;
    }
    /*
     * 给定数组中每个元素都出现两次，只有一个元素例外。找出那个元素
     */
    int singleValue(vector<int> array) {
        int value = 0;
        for (int i = 0; i < array.size(); i++) {
            value ^= array[i];
        }
        return value;
    }
    /*
     * 将N的i到j位设为和M中相同位的值
     */
#define INT_BIT_LENGTH 32
    void setBits(unsigned int &N, unsigned int &M, int i, int j) {
        unsigned int max = ~0;
        unsigned int bitMask = (max << INT_BIT_LENGTH - i) | (max >> j);
        N = (M & (~bitMask)) | (N & bitMask);
    }
    /*
     * 将一个整数中相邻的奇数位和偶数位互换
     */
    int swapBits(int input) {
        return ((0xaaaaaaaa & input) >> 1) | ((0x55555555 & input) << 1);
    }
    /*
     * 交换两个数组
     */
    vector<int> getSwap(vector<int> num) {
        num[0] = num[0] ^ num[1];
        num[1] = num[0] ^ num[1];
        num[0] = num[0] ^ num[1];
        return num;
    }