Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be spe…

看到很多面试书和博客都提到编写atoi函数,在很多面试中面试官都会要求应聘者当场写出atoi函数的实现代码,但基本很少人能写的完全正确,倒不是这道题有多么高深的算法,有多么复杂的数据结构,只因为这道题要考虑的情况比较多,大部分应聘者都没能把所有情况都考虑到,能很好的考察应聘者的编程基本功和思考问题全面性等能力.一看到这道题目我的第一反应是这么简单啊,不就是把一个字符串转化成整数吗?然后速度写下了实现代码,然后测试了下,貌似结果也正确,然后再看了看书和博客上的实现,发现自己很多种情况都没考虑进去,…

#include<iostream> #include<string> #include<vector> using namespace std; void jiema(string s) { cout << "解码之后为:" << endl; ; i < s.size(); i++) { ] == '*') { ; ; ] >= && s[j + ] <= ) { len++; j = j…

问题: Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. 官方难度: Easy 翻译: 实现atoi功能,将一个字符串转化成一个整数. 提示:仔细考虑各种可能出现的情况. 补充资料: 所谓atoi,是C语言库中的一个函数,其功能如下: Requirements for atoi: The function first discards as ma…

1.memcpy函数的原型: void* memcpy(void* dest,cosnt void* src,size_t n); 返回值:返回dest; 功能:从源内存地址src拷贝n个字节到dest内存地址. 这里必须要求源地址的内存和目标地址的内存没有覆盖,如果有覆盖结果是未定义的. #include <stdio.h> #include <assert.h> void* my_memcpy(void* dest,const void* src,size_t n) { ass…

Implement atoi to convert a string to an integer. 转换很简单,唯一的难点在于需要开率各种输入情况,例如空字符串,含有空格,字母等等. 另外需在写的时候注意细节问题,完成后需要反复调试,整合. public class Solution { public int myAtoi(String str) { if (str == null || str.length() < 1) return 0; str = str.trim(); char fla…

Implement atoi to convert a string to an integer. public class Solution { public int myAtoi(String s) { if (s == null || s.length() < 1) { return 0; } int i = 0; while (i < s.length() && s.charAt(i) == ' ') { i++; } if (i == s.length()) { re…

原型:int  atoi (const  char  *nptr) 用法:#include  <stdlib.h> 功能:将字符串转换成整型数:atoi()会扫描参数nptr字符串,跳过前面的空格字符,直到遇上数字或正负号才开始做转换,而再遇到非数字或字符串时('\0')才结束转化,并将结果返回. 说明:atoi()函数返回转换后的整型数. 举例: #include <stdio.h>  #include <stdlib.h>    int main()  {     …

刚看到题就想用数组做,发现大多数解也是用数组做的,突然看到一个清新脱俗的解法: int atoi(const char *str) { ; int n; string s(str); istringstream iss(s); iss>>n; return n; } 代码简洁,核心使用的是istringstream C++串流输入类,该类对象能把字符串对象str读出字符并写入到自定义的各种类型变量中.…

虽然题目中说是easy, 但是我提交了10遍才过,就算hard吧. 主要是很多情况我都没有考虑到.并且有的时候我的规则和答案中的规则不同. 答案的规则: 1.前导空格全部跳过  “      123”  = 123 2.正负号要考虑   “+123” = 123  “-123” = -123 3.数字的前导0要跳过  “-0000123” = “-123” 4.在数字阶段遇到非数字值,数字截断  “-0000 123” = 0   “123a213" = 123 5.没有有效数字,返回0  ”+…

package myAtoi8; /* * Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for…

thanks to http://stackoverflow.com/questions/2144459/using-scanf-to-accept-user-input and http://stackoverflow.com/questions/456303/how-to-validate-input-using-scanf for the i/o part. thanks to http://www.haodaima.net/art/137347 for the rounding part…

标准库函数atoi用于将字符串类型的数据转换为整形数据:在转换过程中要考虑空指针.空字符串"".正负号,溢出等情况 这里是将字符串str转换为32位整型,其正数的最值为0x7FFFFFFF,负数的最小值为0x80000000(可参考有符号类型的最小负数的补码的由来),通过这两个值来判断是上溢还是下溢,此外,用一个全局变量来表明是否是非法输入的问题. 代码如下:(vs2010调试正确) //实现atoi_32函数 //正数数的最大值为0x7FFFFFFF,最小值为0x80000000,考…

题目: Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be…

C语言提供了几个标准库函数C语言提供了几个标准库函数,可以将任意类型(整型.长整型.浮点型等)的数字转换为字符串.以下是用itoa()函数将整数转换为字符串的一个例子: # include <stdio.h> # include <stdlib.h> void main (void) { ; ]; itoa(num, str, ); printf("The number 'num' is %d and the string 'str' is %s. \n" ,…

https://oj.leetcode.com/problems/string-to-integer-atoi/ 细节题,把一个字符串转换成整数 class Solution { public: int atoi(const char *str) { if(str == NULL) ; // remove all spaces ; while(str[i] != '/0' && str[i] == ' ') { i++; } // only contain spaces if(str[i]…

1.int/float to string/array: C语言提供了几个标准库函数,可以将任意类型(整型.长整型.浮点型等)的数字转换为字符串,下面列举了各函数的方法及其说明. ● itoa():将整型值转换为字符串. ● ltoa():将长整型值转换为字符串. ● ultoa():将无符号长整型值转换为字符串. ● gcvt():将浮点型数转换为字符串,取四舍五入. ● ecvt():将双精度浮点型值转换为字符串,转换结果中不包含十进制小数点. ● fcvt():指定位数为转换精度,其余同e…

Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be spe…

String to Integer (atoi) Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended f…

Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be spe…

Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be spe…

本文中调用的四个函数如下: atoi函数:将字符串转化为int类型变量 atol函数:将字符串转化为long类型变量 atoll函数:将字符串转化为long long类型变量 atof函数:将字符串转化为double类型变量 这些函数的转化过程,都是将一个字符串的可读部分取到变量中 遇到不可读的部分,则直接终止读取 调用示例: #include <stdio.h> #include <stdlib.h> #define Seperate(); printf("\n====…

Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be spe…

题目: Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be…

8. String to Integer (atoi) Total Accepted: 112863 Total Submissions: 825433 Difficulty: Easy Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and as…

/* improvement on dealing with overflow accroding to this: * https://discuss.leetcode.com/topic/57452/c-solution-beats-100 * * be careful about the INT_MAX and INT_MIN * this atoi is not thinking about special char like dot and so on. */ class Soluti…

非常考虑思维全面性的一道题,考验是否能够考虑本问题的方方面面. 题目:将一个string转换为int.实现函数atoi()的功能. 先应该明确atoi()有哪些特殊功能:(正常的正负数情况我就不列了) input output ”+1“ 1 ”   +   1“  0(error了) ”       1“ 1(前头只有空格是合法的) ”12b45“ 12(取前面的数字) 溢出 : ”2147483648“(负数情况同) 2147483647(MAX_VALUE) 类似我对atoi()的功能不熟的…

题目: Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is intended for this problem to be…

Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. Notes: It is intended for this problem to be specified vaguely (ie, no given input specs). You are responsible to gather all the input requirements u…

#include<stdio.h> #include<stdlib.h> int sw(char *a){ ,c=; while(a[i]){ ') c=c*+a[i]-'; i++; } ]=='-') c=-c; return c; } int main(){ ],b[]; ],i=; while(scanf("%s %s",a,b)!=EOF) { a1=sw(a); b1=sw(b); c[i]=a1+b1; i++; } ;j<i;j++) pr…