leetcode+string变成整数+注意各种考虑情况

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string>
#include<cstring>
#include<string.h>
#include<math.h>
#include<algorithm>
#include<queue>
#include<vector>
#include<set>
#include<limits.h>
#include<assert.h>
#include<queue>
#define LL long long
#define inf 0x3f3f3f3f
#define mod 1e9+7
using namespace std;
//-+1这种就是错误的，只能返回0
class Solution {
public:
int myAtoi(string str) {
int index=0;
while(str[index]==' ')index++;
int flag=1;
if(str[index]=='-'){
index++;
flag=-1;
}else if(str[index]=='+'){
index++;
}
int res=0;
while(index<str.size()){
if(str[index]<'0' || str[index]>'9'){
return flag*res;
}
int digit=str[index]-'0';
cout<<digit<<endl;
if(flag==1 && res*10.0+digit>INT_MAX){
return INT_MAX;
}else if(flag==-1 && -(res*10.0+digit)<INT_MIN){
return INT_MIN;
}
res = res*10+digit;
cout<<res<<endl;
index++;
}
return flag*res;
}
};
int main()
{
Solution temple;
cout<<temple.myAtoi("-+1");
return 0;
}