ReplaceBlank

#include <iostream>#include <string>using namespace std;void repalce(char str[], int length){    int len = 0, blank = 0;    if (length == 0)        return;    int i = 0;    while (str[i] != '\0')    {        ++len;        if (str[i] == ' ')            blank++;        ++i;    }    int fin_length = len + blank * 2;    /*if (fin_length > length)        return;*/    while (len >= 0)    {        if (str[len] == ' ')        {            str[fin_length--] = '0';            str[fin_length--] = '2';            str[fin_length--] = '%';        }        else        {            str[fin_length--] = str[len];        }        len--;    }}int main(){    string s1;    while (getline(cin, s1))    {        int length = s1.length();        char *str = new char[length * 2];        strcpy(str, s1.c_str());        repalce(str, length);        cout << str << endl;    }    return 0;}