Calcutaor_cli _arg.c

#include<stdio.h>
#include<cs50.h>
#include<string.h>

int main(int argc, string argv[])
{
    if(argc!=4){
        return 1;

    }
    float s,a = atof(argv[1]),b = atof(argv[3]);
    int q;

    if(argv[2][0] == '+'){
        s = a + b;
        printf("The sum is : %f\n",s);
        return 0;
    }

    else if(argv[2][0] == '-'){
        s = a - b;
        printf("The substraction is : %f\n",s);
        return 0;
    }

     else if(argv[2][0] == 'x'){
        s = a * b;
        printf("The multiplication is : %f\n",s);
        return 0;
    }

    else if(argv[2][0] == '/'){
        s = a / b;
        printf("The division is : %f\n",s);
        return 0;
    }

    else if(argv[2][0] == '%'){
        q = (int)(a/b);
        s = a - (b*q);
        printf("The modulo is : %f\n",s);
        return 0;
    }
    else
        return 1;

}