string-problems-cpp/Roman_to_integer.cpp at main · adityaPorwal14/string-problems-cpp · GitHub

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#include <iostream>
#include<string>
using namespace std;

int num(char c) {
    if(c == 'I')
        return 1;

    else if(c=='V')
        return 5;

    else if(c=='X')
        return 10;

    else if(c=='L')
        return 50;

    else if(c=='C')
        return 100;

    else if(c=='D')
        return 500;

    else if(c=='M')
        return 1000;
}


int roman_to_int(string s) {
    int index = 0;
    int sum = 0;

    while(index < s.size()-1) {
        if(num(s[index]) < num(s[index+1])) {
            sum -= num(s[index]);
        }

        else {
            sum += num(s[index]);
        }

        index ++;
    }

    sum += num(s[s.size()-1]);
    return sum;
}

int main() {
    string s;
    cout << "Enter String" << endl;
    cin >> s;

    cout << roman_to_int(s);
}