CareerCup1.4.cpp

CareerCup1.4.cpp

/* Chapter 1
 * 1.4 Write a method to replace all the space in a string to %20
 * you may assume the given space is sufficient.
 * Example: "Mr John Troy(_extra_space_)"
 *        =>"Mr%20John%20Troy."
 */


#include <iostream>
#include <string>

using namespace std;

void replace(char* str)
{
    int counter = 0;
    for (int i = 0; i < strlen(str) - 1; ++i)
    {
        if (str[i] == ' ' && str[i+1] != ' ')
        {
            counter++;
        }
    }
    
    int extend_len = strlen(str) + 2 * counter;
    str[extend_len] = '\0'; // assign memory space
    char* p = str + extend_len - 1;

    for(int i = strlen(str) - 1; i >= 0; i--)
    {
        if (str[i] == ' ')
        {
            *p-- = '0';
            *p-- = '2';
            *p-- = '%';
        }
        else
            *p-- = str[i];
    }
}

// Main Function

int main(int argc, char const *argv[])
{
    char str[] = "Mr John Troy.";
    replace(str);
    cout << str << endl;
    return 0;
}