Path in a directed graph

Write an algorithm to find if a path exists between two nodes in a directed graph.

1 ————> 2 ————> 3
        ↑       |
        |       |
        |       ↓
        4 ————> 5 ————> 6

Answer:

#include "stdio.h"
#include "stdlib.h"
#include "assert.h"

#define IS_CONNECTED(from,to) graph[(from-1)][(to-1)]

int graph[6][6]= {
                {0, 1, 0, 0, 0, 0},
                {0, 0, 1, 0, 0, 0},
                {0, 0, 0, 0, 1, 0},
                {0, 1, 0, 0, 1, 0},
                {0, 0, 0, 0, 0, 1},
                {0, 0, 0, 0, 0, 0}
               };

bool isReachable(size_t from, size_t to)
{
    const int n = 6;
    printf("\n isReachable %d -> %d \n", from, to );
    if ( from == to )
        return true;
    if(IS_CONNECTED(from, to))
        return true;
    else
    {
        for( size_t i =1; i <= n; ++i )
        {
            if( IS_CONNECTED(i,to) )
            {
                if (isReachable( from, i))
                    return true;
                continue;
            }
        }
        return false;
    }
}

int main(int argc, char* argv[])
{
    size_t from = atoi(argv[1]);
    size_t to = atoi(argv[2]);
    assert( (from <= 6) && (from >=1) );
    assert( (to <= 6) && (to >=1) );
    return printf("\n Is Reachable(%d -> %d) %d\n", from, to, isReachable(from, to ));
}