8. String to Integer (atoi)

C++ | 100% Success | Brute Force | Easy Understanding

class Solution {
public:
    int myAtoi(string s) {
        int sign = 1;
        int i = 0;
        long long int ans = 0;
        while(s[i]==' ')i++;
        if(s[i]=='-'){
            sign = -1;
            i++;
        }
        else if(s[i]=='+') i++;
        int u = INT_MAX;
        int l = INT_MIN;
        int j = i;
        while(s[j]>='0' && s[j]<='9'){
            if(s[j]==' ') continue;
            ans += s[j] - '0';
            if(sign*ans<=l)return l;
            else if(sign*ans>=u) return u;
            ans = ans * 10;
            j++;
        }
        ans = ans /10;
        ans  = ans*sign;
        return (int)ans;
        
    }
};