类型转换 char[]转 int

​​经典算法无需注释​​

#include<bits/stdc++.h>
using namespace std;
map<int,int> M[100];
int toInt(char ch[],int s,int e)
{
    int result = 0;
    for(int i = s;i < e;i++)
    {
        result = result*10+ch[i]-'0';
    }
    return result;
}
int main()
{
   char ch[] = "123";
   string s = to_string(123);
   cout << s << endl;
   int a = toInt(ch,0,1);
   cout << a << endl;
}