Hello

I'm having trouble getting my program to do what it needs because i don't completely understand how linked lists work. If i could get a some help i'd greatly appreciate it. I mainly need help with making it go through the 1,000 time steps, remove cars that have crashed, and debugging a few problems.

Here's the question:

Consider a square domain partitioned into 250,000 equally spaced grid cells (500 by 500). We will randomly distribute some cars into this domain such that no more than 1 car is located in any grid cell initially. Each car has a random mass between 1-50. At each time step of the simulation, each car randomly moves one grid cell in the x or y direction (4 possible directions). If a car touches the edges of the domain then it “rebounds” 180o towards the interior. If two cars land on the same grid cell, then they have had an accident, and the smaller car is removed from the simulation.

Write a program to simulate this system. Use structures to represent the cars in the simulation. Make your program efficient by only allocating memory for active cars, and free memory for cars that are no longer active. Hint: use a linked list to represent the cars.

Show the initial distribution of cars and the final distribution of surviving cars (the

number of cars at each possible mass) after 1000 time steps if the simulation starts with 500 and 2000 cars (2 cases). Make a histogram of your results using excel. The bins on the x-axis of the histogram will be the mass of each car. The value on the y-axis will be the number of cars in each bin.

Here's my code:

Code://prototype definitions #include<stdio.h> #include<stdlib.h> //structure for x,y,and weight of an array of cars typedef struct{ float x; float y; float weight; struct car_s *next; } car_t; int main () { //local variable definitions to randomize location and weight int i = 0; int X = rand() % 500; int Y = rand() % 500; int Weight = rand() % 50; float car[500]={X, Y, Weight}; car *cptr = car_t[i]; car[i]={X,Y,Weight}; //loop through the linked list among the 500 possible cars for(i=0; i<=500; i++) { cptr-> nextptr=malloc(sizeof(struct car_t)); cptr->x=rand() % 500; cptr->y=rand() % 500; cptr->weight = rand() % 50; // printf("car %d has position %d, %d and weight %d\n", i, car_t.x, car_t.y, car_t.weight); } cptr->nextptr=NULL; return; } //Function for the location of the cars. int location(int) { int m[5] = rand() % 4; int g = 5; //loop through the different randimizations for (i=0; i<=g; i++) { if(m==1) car[i].x=rand() % (X+1); if(m==2) car[i].x=rand() % (X-1); if(m==3) car[i].y=rand() % (Y+1); if(m==4) car[i].y=rand() % (Y-1); } return m; } //Function to check for collisions int check(int) { int ix=0; int iy=0; //loop checking for collisions for(i=0; i<=500; i++) { for(ix=0; ix<=500; ix++) { for(iy=0; iy<=500; iy++) { if(iy=ix) car[i].x= 0 car[i].y= 0 } } } return 0; }

-Any help or alterations you see neccessary would be of great appreciation

Thanks