HACKERRANK tree-huffman-decoding Solution

| August 24, 2016

The correct, optimal and working solution for programming question tree-huffman-decoding on hackerrank

/*
 *  Author: Arpit Bhayani
 *  http://arpitbhayani.me
 */
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <climits>
#include <deque>
#include <iostream>
#include <list>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>

#define ll long long

#define MIN(a, b) a < b ? a : b
#define MAX(a, b) a > b ? a : b

using namespace std;

int readline(char *str) {
    int i = 0;
    char ch;
    while((ch = getchar()) != '\n') {
        str[i++] = ch;
    }
    str[i] = '\0';
    return i;
}

struct node {
    int freq;
    char data;
    struct node * left;
    struct node * right;
};

struct node * new_node(int freq, char data) {
    struct node * t = (struct node *) calloc(1, sizeof(struct node));
    t->data = data;
    t->freq = freq;
    return t;
}

void decode_huff(struct node * root, string s) {
    struct node * p = root;
    for(int i = 0 ; s[i]; i++) {

        if(s[i] == '0') {
            p = p->left;
        }
        else {
            p = p->right;
        }

        if(p->left == NULL && p->right == NULL) {
            printf("%c", p->data);
            p = root;
        }
    }
    printf("\n");
}


int main(int argc, char *argv[]) {
    struct node * root = new_node(5, '\0');
    root->left = new_node(2, '\0');
    root->right = new_node(3, 'A');

    root->left->left = new_node(1, 'B');
    root->left->right = new_node(1, 'C');

    string s = "1001011";

    decode_huff(root, s);

    return 0;
}