leetcode剑指Offer 二分查找(简单)

• 剑指 Offer 11. 旋转数组的最小数字
• 剑指 Offer 53 - II. 0～n-1中缺失的数字
• 剑指 Offer 11. 旋转数组的最小数字

题目

public int minArray(int[] numbers) {
    int i = 0, j = numbers.length - 1;
    while (i < j) {
        int m = (i + j) / 2;
        if (numbers[m] > numbers[j]) i = m + 1;
        else if (numbers[m] < numbers[j]) j = m;
        else j--;
    }
    return numbers[i];
}

题目

public int missingNumber(int[] nums) {
    int i = 0, j = nums.length - 1;
    while(i <= j) {
        int m = (i + j) / 2;
        if(nums[m] == m) i = m + 1;
        else j = m - 1;
    }
    return i;
}

题目

public int minArray(int[] numbers) {
    int low = 0;
    int high = numbers.length - 1;
    while (low < high) {
        int pivot = low + (high - low) / 2;
        if (numbers[pivot] < numbers[high]) {
            high = pivot;
        } else if (numbers[pivot] > numbers[high]) {
            low = pivot + 1;
        } else {
            high -= 1;
        }
    }
    return numbers[low];
}