eclipse没问题,leetcode 1不能通过,超出int最大值了,但是怎么转无符号? /*Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight). For example, the 32-bit integer ’11' has binary representation 0000000000000…

Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as00111001011110000010100101000000). Follow up:If this function i…

(记忆线:当时一刷完是1-205. 二刷88道.下次更新记得标记不能bug-free的原因.)   88-------------Perfect Squares(完美平方数.给一个整数,求出用平方数来相加得到最小的个数) public class Solution{ public static void main(String[] args){ System.out.println(numSquares(8)); } public static int numSquares(int n){ //…

#190. Reverse Bits Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000). 题解:移位运算.…

按位操作符只能用于整数基本数据类型中的单个bit中,操作符对应表格: Operator Description & 按位与(12345&1=1,可用于判断整数的奇偶性) | 按位或 ^ 异或(同假异真) ~ 非(一元操作符) &=,|=,^= 合并运算和赋值 <<N 左移N位,低位补0 >>N 右移N位,(正数:高位补0,负数高位补1) >>>N 无符号右移(无论正负数,高位皆补0) <<=,>>=,>>…

463. Island Perimeterhttps://leetcode.com/problems/island-perimeter/就是逐一遍历所有的cell,用分离的cell总的的边数减去重叠的边的数目即可.在查找重叠的边的数目的时候有一点小技巧,就是沿着其中两个方向就好,这种题目都有类似的规律,就是可以沿着上三角或者下三角形的方向来做.一刷一次ac,但是还没开始注意codestyle的问题,需要再刷一遍. class Solution { public: int islandPerime…

2.Add Two Numbers 原题链接https://leetcode.com/problems/add-two-numbers/ AC解: public ListNode addTwoNumbers(ListNode l1, ListNode l2) { int sum = 0; ListNode head = new ListNode(0); ListNode dummy = new ListNode(0); ListNode flag = dummy; dummy.next = he…

190. Reverse Bits Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000). Follow up…

Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as00111001011110000010100101000000). 思路: n一直右移, ans一直左移. class So…

#-*- coding: UTF-8 -*- class Solution:    # @param n, an integer    # @return an integer    def reverseBits(self, n):        tmp=str(bin(n))[2:][::-1]                for i in xrange(32-len(tmp)):            tmp+='0'               return int(tmp,base=…