ADVANCED DATA STRUCTURES PROGRAM • LEVEL 16 — MULTIWAY SEARCH TREES

Promote the Median in a 2–3 Tree

Learn how to promote the median in a 2–3 tree using a clear C program.

AdvancedB-treeMultiway search

PROBLEM UNDERSTANDING

Input and expected output

Sample input

No input required

Sample output

Promote = 20 Left = 10 Right = 30

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    int keys[] = {30, 10, 20};
    for (int i = 1; i < 3; i++) { int value = keys[i], j = i - 1; while (j >= 0 && keys[j] > value) { keys[j + 1] = keys[j]; j--; } keys[j + 1] = value; }
    printf("Promote = %d Left = %d Right = %d\n", keys[1], keys[0], keys[2]); return 0;
}

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

Promote = 20 Left = 10 Right = 30

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Sort the overflowing node's three keys, promote the middle and retain one key per child.
Display the computed result.

Sort the overflowing node's three keys, promote the middle and retain one key per child.

EFFICIENCY

Time and space complexity

Time complexity

O(1) for a 3-key overflow

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

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Use the correct format specifier for every variable.

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Initialize variables before using their values.

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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.