This C++ Program to Find All Pairs Shortest Path in a Graph.

Here is source code of the C++ Program to Find All Pairs Shortest Path using Floyd’s Algorithm. The C++ program is successfully compiled and run on a Linux system. The program output is also shown below.

`/*`

`* C++ Program to Find All Pairs Shortest Path`

`*/`

`#include <iostream>`

`#include <cstdlib>`

`#define max 10`

`#define infi 999`

using namespace std;

int p[max][max];

`/*`

`* All Pairs Shortest Path using Floyd's Algorithm`

`*/`

void allpairshort(int a[max][max], int n)

`{`

int k, i, j;

for (k = 0; k < n; k++)

`{`

for (i = 0; i < n; i++)

`{`

for (j = 0; j < n; j++)

`{`

if (a[i][k] + a[k][j] < a[i][j])

`{`

a[i][j] = a[i][k] + a[k][j];

p[i][j] = k;

`}`

`}`

`}`

`}`

`}`

`/*`

`* Storing the shortest path`

`*/`

void shortest(int i, int j)

`{`

int k = p[i][j];

if (k > 0)

`{`

shortest(i, k);

cout<<" "<<k<<" ";

shortest(k, j);

`}`

`}`

`/*`

`* Display the Shortest Path`

`*/`

void findpath(int a[max][max], int i, int j, int n)

`{`

cout<<"Path from " << i <<" to "<< j << ":";

if (a[i][j] < infi)

`{`

cout<<" "<<i<<" ";

shortest(i, j);

cout<<" "<<j<<" ";

`}`

`}`

`/*`

`* Main Contains Menu`

`*/`

int main()

`{`

int i, j;

int a[][10] = {{0, 10, infi, 30, 100},

{infi, 0 , 50, infi, infi},

{infi, infi , 0, infi, 10},

{infi, infi , 20, 0, 60},

{infi, infi , infi, infi, 0},

};

allpairshort(a, 5);

findpath(a, 0, 4, 5);

return 0;

`}`

$ g++ allpairshortestpath.cpp $ a.out Path from 0 to 4: 0 3 2 4 ------------------ (program exited with code: 1) Press return to continue

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