34. 在排序数组中查找元素的第一个和最后一个位置

class Solution {
    public int[] searchRange(int[] nums, int target) {
        int[] a = new int[2];
        a[0] = binarySearch1(nums,target);
        a[1] = binarySearch2(nums,target);
        return  a;
    }

    public int binarySearch1(int[] nums, int target) {
        int left = 0;
        int right = nums.length - 1;
        int leftI = -1;
        while(left <= right){
            int mid = (left + right) / 2;
            if (nums[mid] == target){ //若找到了一个，我们在（left, mid-1）中继续找，直到找到最左边的那一个。
                leftI  = mid;
                right = mid - 1;
            }
            if (nums[mid] > target){
                right = mid - 1;
            }
            if (nums[mid] < target){
                left = mid + 1;
            }
        }
        return leftI;
    }
    public int binarySearch2(int[] nums, int target) {
        int left = 0;
        int right = nums.length - 1;
        int rightI = -1;
        while(left <= right){
            int mid = (left + right) / 2;
            if (nums[mid] == target){ // //若找到了一个，我们在（mid+1,right）中继续找，直到找到最右边的那一个。
                rightI  = mid;
                left = mid + 1;
            }
            if (nums[mid] > target){
                right = mid - 1;
            }
            if (nums[mid] < target){
                left = mid + 1;
            }
        }
        return rightI;
    }
}
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