Why my code is giving wrong answer for Traveling Plan Problem

Can any body tell me why my code is giving wrong answer ?

Algorithm :

unsigned long max -> will contain the final max waiting time in optimal case
unsigned long t -> T
unsigned long m -> M
unsigned long n -> N

int main(void)
{
unsigned long busses[m+1][4] -> Contains bus information
busses[][0] -> U -> starting station
busses[][1] -> V -> Ending station
busses[][2] -> S -> Start time
busses[][3] -> E -> End time

busses[m+1][4] -> Initialized with 0

unsigned long stations[n+1][m] -> Tells available busses at a particular station
like -> busses 2 and 3 start from station 3 then
stations[3][0] -> 2
stations[3][1] -> 3
stations[3][2] to stations[3][m] -> 0

step 1 -> read input values in busses matrix

step 2 -> accordingly fill matrix stations

step 3 -> timestamp -> 0 -> current time
temp -> 0 -> current max waiting time

step 4 -> call function function which will give the final answer max
function(1,&temp,timestamp,stations,busses)

      1 -> tells the **first station** since we have to start from staion 1

step 5 -> print final value

}

void function(station , *temp , timestamp, stations, busses)
{
step 1 -> if (station == n)
{
if (*temp < max)
{
max = *temp
}
}
step -> 2 else
{
step -> 3 while(there is a bus from station station)
{
if(waiting time > *temp)
{
*temp = waiting time;
}

                    update timestamp -> timetamp = end time of buss

                    call function **function ** with ending time of bus 

                    function(ending station of current bus , &temp , timestamp , stations , busses)
              }

      }

}

**here is my code : **

#include<stdio.h>
#include<stdlib.h>
#include<limits.h>
#include<memory.h>

unsigned long max,t,m,n;

void function(unsigned long station , unsigned long *temp , unsigned long timestamp,unsigned long stations[n+1][m], unsigned long busses[m+1][4])
{
if(station == n)
{
if(*temp < max)
{
max = *temp;
}
}
else
{
unsigned long counter = 0;

	while(stations[station][counter] != 0)
	{
		if((busses[stations[station][counter]][2] - timestamp ) > *temp)
		{
			*temp = busses[stations[station][counter]][2] - timestamp;
		}

		timestamp = busses[stations[station][counter]][3];
		function(busses[stations[station][counter]][1],temp,timestamp,stations,busses);

		counter++;
	}
}

}

int main(void)
{
max = UINT_MAX;

scanf("%lu",&n);
scanf("%lu",&t);
scanf("%lu",&m);

unsigned long  busses[m+1][4];

memset(busses,0,sizeof(busses[0][0])*(m+1)*4);

unsigned long  stations[n+1][m] ;

memset(stations,0,sizeof(stations[0][0])*(n+1)*m);

unsigned long i;
unsigned long  counter;

for(i=1;i<=m;i++)
{
	scanf("%lu",&busses[i][0]);

	counter=0;

	while(stations[busses[i][0]][counter] != 0)
	{
		counter++;
	}

	stations[busses[i][0]][counter] = i;

	scanf("%lu",&busses[i][1]);

	scanf("%lu",&busses[i][2]);

	scanf("%lu",&busses[i][3]);
}

unsigned long timestamp =0;
unsigned long  temp=0;

function(1,&temp,timestamp,stations,busses);



if(max != UINT_MAX)
{
	printf("%lu\n",max);	
}
else
{
	printf("-1\n");
}

return 0;

}

//