023-在排序数组中查找元素的第一个和最后一个位置 (Find First and Last Position of Element in Sorted Array)

输入: nums = [5,7,7,8,8,10], target = 8
输出: [3,4]

输入: nums = [5,7,7,8,8,10], target = 6
输出: [-1,-1]

输入: nums = [], target = 0
输出: [-1,-1]

输入: nums = [1], target = 1
输出: [0,0]

输入: nums = [2,2], target = 2
输出: [0,1]

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
const searchRange = function(nums, target) {
    // 查找左边界
    const findLeft = (nums, target) => {
        let left = 0;
        let right = nums.length - 1;
        let result = -1;
        
        while (left <= right) {
            const mid = Math.floor((left + right) / 2);
            
            if (nums[mid] === target) {
                result = mid;
                right = mid - 1; // 继续向左查找
            } else if (nums[mid] < target) {
                left = mid + 1;
            } else {
                right = mid - 1;
            }
        }
        
        return result;
    };
    
    // 查找右边界
    const findRight = (nums, target) => {
        let left = 0;
        let right = nums.length - 1;
        let result = -1;
        
        while (left <= right) {
            const mid = Math.floor((left + right) / 2);
            
            if (nums[mid] === target) {
                result = mid;
                left = mid + 1; // 继续向右查找
            } else if (nums[mid] < target) {
                left = mid + 1;
            } else {
                right = mid - 1;
            }
        }
        
        return result;
    };
    
    const left = findLeft(nums, target);
    const right = findRight(nums, target);
    
    return [left, right];
};

// 测试函数
function testSearchRange() {
    const testCases = [
        { nums: [5,7,7,8,8,10], target: 8, expected: [3,4] },
        { nums: [5,7,7,8,8,10], target: 6, expected: [-1,-1] },
        { nums: [], target: 0, expected: [-1,-1] },
        { nums: [1], target: 1, expected: [0,0] },
        { nums: [2,2], target: 2, expected: [0,1] },
        { nums: [1,2,3,4,5], target: 3, expected: [2,2] },
        { nums: [1,1,1,1,1], target: 1, expected: [0,4] },
        { nums: [1,2,3,4,5], target: 6, expected: [-1,-1] },
        { nums: [1,2,3,4,5], target: 0, expected: [-1,-1] },
        { nums: [1,1,2,2,3,3], target: 2, expected: [2,3] },
        { nums: [1,1,2,2,3,3], target: 1, expected: [0,1] },
        { nums: [1,1,2,2,3,3], target: 3, expected: [4,5] }
    ];
    
    testCases.forEach((testCase, index) => {
        const result = searchRange(testCase.nums, testCase.target);
        const passed = JSON.stringify(result) === JSON.stringify(testCase.expected);
        console.log(`测试用例 ${index + 1}: ${passed ? '✅' : '❌'}`);
        console.log(`输入: nums = [${testCase.nums}], target = ${testCase.target}`);
        console.log(`期望: [${testCase.expected}]`);
        console.log(`实际: [${result}]`);
        console.log('---');
    });
}

// 运行测试
testSearchRange();