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

/* * Author: Arpit Bhayani * https://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; }