TheAlgorithms-C/data_structures/graphs/transitiveclosure.c

#include <stdbool.h>
#include <stdio.h>

#define NODES 4

int digraph[NODES][NODES] = {
    {0, 1, 1, 1}, {1, 0, 1, 0}, {0, 1, 0, 0}, {0, 0, 0, 0}};
int tc[NODES][NODES];

void warshall()
{
    int i, s, t;
    for (s = 0; s < NODES; s++)
        for (t = 0; t < NODES; t++) tc[s][t] = digraph[s][t];

    for (i = 0; i < NODES; i++)
        for (s = 0; s < NODES; s++)
            for (t = 0; t < NODES; t++)
                if (tc[s][i] && tc[i][t])
                    tc[s][t] = 1;
}

int main(void)
{
    warshall();
    int i, j;
    for (i = 0; i < NODES; i++)
    {
        for (j = 0; j < NODES; j++)
        {
            printf("%d ", tc[i][j]);
        }
        putchar('\n');
    }
    return 0;
}

// By
//  .----------------.  .----------------.  .----------------.
//  .-----------------.  .----------------.  .----------------.
// | .--------------. || .--------------. || .--------------. ||
// .--------------. | | .--------------. || .--------------. | | |  _________ |
// || | _____  _____ | || |      __      | || | ____  _____  | | | |  ____  ____
// | || |     ____     | | | | |  _   _  |  | || ||_   _||_   _|| || |     /  \
// | || ||_   \|_   _| | | | | |_   ||   _| | || |   .'    `.   | | | | |_/ | |
// \_|  | || |  | |    | |  | || |    / /\ \    | || |  |   \ | |   | | | |   |
// |__| |   | || |  /  .--.  \  | | | |     | |      | || |  | '    ' |  | || |
// / ____ \   | || |  | |\ \| |   | | | |   |  __  |   | || |  | |    | |  | |
// | |    _| |_     | || |   \ `--' /   | || | _/ /    \ \_ | || | _| |_\   |_
// | | | |  _| |  | |_  | || |  \  `--'  /  | | | |   |_____|    | || | `.__.'
// | || ||____|  |____|| || ||_____|\____| | | | | |____||____| | || | `.____.'
// | | | |              | || |              | || |              | || | | | | |
// | || |              | | | '--------------' || '--------------' ||
// '--------------' || '--------------' | | '--------------' || '--------------'
// |
//  '----------------'  '----------------'  '----------------'
//  '----------------'   '----------------'  '----------------'

//  Email :    z5261243@unsw.edu.au
//             hhoanhtuann@gmail.com