m0_46293802的博客

1.索引 class Solution { public int romanToInt(String s) { int sum = 0; int preNum = switchcase(s.charAt(0)); for(int i = 1;i < s.length(); i ++) { int num = switchcase(s.charAt(i)); if(preNum < num)

1.暴力 涉及到把整数转化为字符串，再把字符串分割为数组 第一次见 class Solution { public boolean isPalindrome(int x) { String reversedStr = (new StringBuilder(x + "")).reverse().toString(); return (x + "").equals(reversedStr); } } 2.取头尾比较 class Solution { pu

class Solution { public int reverse(int x) { int rev = 0; while (x != 0) { int pop = x % 10; x /= 10; if (rev > Integer.MAX_VALUE/10 || (rev == Integer.MAX_VALUE / 10 && pop > 7)) return

package 二分查找; import java.util.Scanner; public class Binsearch { public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner in = new Scanner(System.in); System.out.println("请输入你要查找的...

1.两指针（更快，适合已排序好的数组） class Solution { public int[] twoSum(int[] numbers, int target) { int i=0,j=numbers.length-1; while(i<j){ if(numbers[i]+numbers[j]==target){ return new int[]{i+1,j+1}; }