字符串转整数

将输入的字符串转换为整数。输入：字符串 输出：整数

函数原型：int zifu2sz(char *str)

#include<stdlib.h>#include<stdio.h>int zifu2sz(char *str){int sum=0;int flag;if(*str=='-'){flag=1;str++;}else flag=0;while(*str){sum=10*sum+((*str)-'0');str++;}if(flag==1)return (sum*(-1));    else return sum;}void main(){int n;char *str="-1243";n=zifu2sz(str);printf("%d\n",n);}