ADVANCED DATA STRUCTURES PROGRAM • LEVEL 9 — DISJOINT SETS
Compress Paths During Find
Learn how to compress paths during find using a clear C program.
PROBLEM UNDERSTANDING
Input and expected output
Sample input
No input required
Sample output
Before = 3 After = 0
COMPLETE C PROGRAM
Complete C implementation
#include <stdio.h>
int parent[10], rank_value[10], set_size[10];
void initialize(int count) { for (int i = 0; i < count; i++) { parent[i] = i; rank_value[i] = 0; set_size[i] = 1; } }
int find_root(int value) { return parent[value] == value ? value : (parent[value] = find_root(parent[value])); }
void unite_rank(int first, int second)
{
first = find_root(first); second = find_root(second);
if (first == second) return;
if (rank_value[first] < rank_value[second]) { int temp = first; first = second; second = temp; }
parent[second] = first; set_size[first] += set_size[second];
if (rank_value[first] == rank_value[second]) rank_value[first]++;
}
int main(void)
{
initialize(5);
parent[4] = 3; parent[3] = 2; parent[2] = 1; parent[1] = 0;
printf("Before = %d ", parent[4]);
find_root(4);
printf("After = %d\n", parent[4]);
return 0;
}CURRENT STEP
SELECTED LINE
EXPECTED OUTPUT FOR THE SAMPLE
Before = 3 After = 0
Step 0 of 0
PROGRAM EXPLANATION
Algorithm and explanation
- Read the required input values.
- Rewrite every visited parent to point directly to the representative.
- Display the computed result.
Rewrite every visited parent to point directly to the representative.
EFFICIENCY
Time and space complexity
Time complexity
O(alpha(n)) amortized
Auxiliary space
O(n)
DEBUGGING CHECKLIST
Common mistakes
Check this
Use the correct format specifier for every variable.
Check this
Initialize variables before using their values.
Check this
Check braces, semicolons and input order carefully.
Try it yourself
Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.
