How to use multiple pointers to a struct that contains a pointer to another struct with mutiple pointers?

I am trying to use an array of pointers to a struct that has a pointer in it to another struct that is being used with an array of pointers.

I can write the code for a two single structs and it works. However, I am not sure how to deal with the introduction of the array of pointers. Sample code:

typedef struct {      double vx;  } particle_t;        typedef struct {      int m;      int n;      particle_t *inparticles;    // Pointer to particles inside grid  } grid_t;        particle_t *particles = (particle_t*) malloc( 3 * sizeof(particle_t) );  grid_t *grid = (grid_t*) malloc( 3 * sizeof(grid_t) ); // trying 3 pointers    if( particles==NULL || grid==NULL ){      puts("Unable to allocate memory");      exit(1);}    // fill the structure   grid[1].inparticles = particles[1]; // I am not sure how to link these  grid[2].inparticles = particles[2]; // these lines give incompatible types error  grid[3].inparticles = particles[3];  grid[1].m = 5;  grid[1].n = 3;  grid[1].inparticles -> vx = 15;  

Thank you in advance!

Update:

I realized that what I should be doing is use the inparticles pointer to point to multiple particles in the same grid pointer? How I can change the code so I can be able to do that? for example:

grid[0].inparticles[0] = particles[0];  grid[0].inparticles[1] = particles[1];  grid[0].inparticles[2] = particles[2];  

declare it as an array somehow? would I need memory allocation for it as well?

https://stackoverflow.com/questions/66576699/how-to-use-multiple-pointers-to-a-struct-that-contains-a-pointer-to-another-stru March 11, 2021 at 12:55PM