LeetCode learning records based on Java,Kotlin,Python...
序号对应 LeetCode 中题目序号
1 两数之和
给定一个整数数列，找出其中和为特定值的那两个数,你可以假设每个输入都只会有一种答案，同样的元素不能被重用;
- Java 语言实现
public int[] twoSum(int[] nums, int target) { int i, j; for (i = 0; i < nums.length; i++) { for (j = i + 1; j < nums.length; j++) { int sun = nums[i] + nums[j]; if (target == sun) { return new int[]{i, j}; } } } return new int[]{-1, -1}; } - Kotlin 语言实现
fun twoSum(nums: IntArray, target: Int): IntArray { var sum: Int for (i: Int in nums.indices) { for (j: Int in i+1 until nums.lastIndex+1) { sum = nums[i] + nums[j] if (target == sum) { return intArrayOf(i,j) } } } return intArrayOf(-1,-1) } 7 给定一个范围为 32 位 int 的整数，将其颠倒
- Java 语言实现
public static int reverse(int x) { int result; int startLen = 0; String str = String.valueOf(x); if (str.charAt(0) == '-') { startLen = 1; } if (str.length() == 1) { return x; } int lastLen = str.length() - 1; String readStr = ""; while (lastLen >= startLen) { readStr = readStr + str.charAt(lastLen); lastLen--; } try { result = Integer.parseInt(readStr); }catch (NumberFormatException e){ return 0; } return startLen == 0 ? result : result * (-1); } *Kotlin 语言实现
fun reverse(x: Int): Int { var startLen = 0 if (x < 0) { startLen = 1 } val str = x.toString() if (str.length == 1) { return x } var lastLen = str.length - 1 var readStr = "" while (lastLen >= startLen) { readStr += str[lastLen] lastLen-- } return try { if (startLen == 0) { readStr.toInt() } else { readStr.toInt() * (-1) } } catch (e: NumberFormatException) { 0 } }