ADVANCED DATA STRUCTURES PROGRAM • LEVEL 20 — ADVANCED GRAPH ALGORITHMS

Find Bridges with Tarjan Low-Link Values

Learn how to find bridges with tarjan low-link values using a clear C program.

AdvancedAdvanced graphsGraph optimization

PROBLEM UNDERSTANDING

Input and expected output

Sample input

No input required

Sample output

Bridge = 3-4
Bridge = 1-3

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

void dfs(int node,int parent,int graph[5][5],int visited[],int tin[],int low[],int*timer){visited[node]=1;tin[node]=low[node]=(*timer)++;for(int next=0;next<5;next++)if(graph[node][next]){if(next==parent)continue;if(visited[next]){if(tin[next]<low[node])low[node]=tin[next];}else{dfs(next,node,graph,visited,tin,low,timer);if(low[next]<low[node])low[node]=low[next];if(low[next]>tin[node])printf("Bridge = %d-%d\n",node,next);}}}

int main(void)
{
    int graph[5][5]={{0,1,1,0,0},{1,0,1,1,0},{1,1,0,0,0},{0,1,0,0,1},{0,0,0,1,0}},visited[5]={0},tin[5],low[5],timer=0;dfs(0,-1,graph,visited,tin,low,&timer);return 0;
}

CURRENT STEP

Select Start to walk through the important lines.

SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

Bridge = 3-4
Bridge = 1-3

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
An edge to a DFS child is a bridge when the child subtree cannot reach the parent's discovery time.
Display the computed result.

An edge to a DFS child is a bridge when the child subtree cannot reach the parent's discovery time.

EFFICIENCY

Time and space complexity

Time complexity

O(V + E)

Auxiliary space

O(V + E)

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.