From ef1b6f58a04e14c8e30bbbb368d79f6d8a05fa9c Mon Sep 17 00:00:00 2001
From: fredrikr79 <fredrikrobertsen7@gmail.com>
Date: Mon, 22 Sep 2025 16:28:44 +0200
Subject: [PATCH] ex3: style

---
 exercise3/wave_1d_parallel.c | 206 +++++++++++++++--------------------
 1 file changed, 88 insertions(+), 118 deletions(-)

diff --git a/exercise3/wave_1d_parallel.c b/exercise3/wave_1d_parallel.c
index 48f22e5..ef9847c 100644
--- a/exercise3/wave_1d_parallel.c
+++ b/exercise3/wave_1d_parallel.c
@@ -1,9 +1,9 @@
 #define _XOPEN_SOURCE 600
+#include <math.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdint.h>
-#include <math.h>
 #include <sys/time.h>
 
 // TASK: T1a
@@ -12,19 +12,16 @@
 ;
 // END: T1a
 
-
 // Option to change numerical precision.
 typedef int64_t int_t;
 typedef double real_t;
 
-
 // TASK: T1b
 // Declare variables each MPI process will need
 // BEGIN: T1b
 ;
 // END: T1b
 
-
 // Simulation parameters: size, step count, and how often to save the state.
 const int_t
     N = 65536,
@@ -33,7 +30,7 @@ const int_t
 
 // Wave equation parameters, time step is derived from the space step.
 const real_t
-    c  = 1.0,
+    c = 1.0,
     dx = 1.0;
 real_t
     dt;
@@ -42,164 +39,137 @@ real_t
 real_t
     *buffers[3] = { NULL, NULL, NULL };
 
-
-#define U_prv(i) buffers[0][(i)+1]
-#define U(i)     buffers[1][(i)+1]
-#define U_nxt(i) buffers[2][(i)+1]
-
+#define U_prv(i) buffers[0][(i) + 1]
+#define U(i) buffers[1][(i) + 1]
+#define U_nxt(i) buffers[2][(i) + 1]
 
 // Convert 'struct timeval' into seconds in double prec. floating point
 #define WALLTIME(t) ((double)(t).tv_sec + 1e-6 * (double)(t).tv_usec)
 
-
 // TASK: T8
 // Save the present time step in a numbered file under 'data/'.
-void domain_save ( int_t step )
-{
-// BEGIN: T8
-    char filename[256];
-    sprintf ( filename, "data/%.5ld.dat", step );
-    FILE *out = fopen ( filename, "wb" );
-    fwrite ( &U(0), sizeof(real_t), N, out );
-    fclose ( out );
-// END: T8
+void domain_save(int_t step) {
+  // BEGIN: T8
+  char filename[256];
+  sprintf(filename, "data/%.5ld.dat", step);
+  FILE *out = fopen(filename, "wb");
+  fwrite(&U(0), sizeof(real_t), N, out);
+  fclose(out);
+  // END: T8
 }
 
-
 // TASK: T3
 // Allocate space for each process' sub-grids
 // Set up our three buffers, fill two with an initial cosine wave,
 // and set the time step.
-void domain_initialize ( void )
-{
-// BEGIN: T3
-    buffers[0] = malloc ( (N+2)*sizeof(real_t) );
-    buffers[1] = malloc ( (N+2)*sizeof(real_t) );
-    buffers[2] = malloc ( (N+2)*sizeof(real_t) );
+void domain_initialize(void) {
+  // BEGIN: T3
+  buffers[0] = malloc((N + 2) * sizeof(real_t));
+  buffers[1] = malloc((N + 2) * sizeof(real_t));
+  buffers[2] = malloc((N + 2) * sizeof(real_t));
 
-    for ( int_t i=0; i<N; i++ )
-    {
-        U_prv(i) = U(i) = cos ( 2*M_PI*i / (real_t)N );
-    }
-// END: T3
+  for (int_t i = 0; i < N; i++) {
+    U_prv(i) = U(i) = cos(2 * M_PI * i / (real_t)N);
+  }
+  // END: T3
 
-    // Set the time step for 1D case.
-    dt = dx / c;
+  // Set the time step for 1D case.
+  dt = dx / c;
 }
 
-
 // Return the memory to the OS.
-void domain_finalize ( void )
-{
-    free ( buffers[0] );
-    free ( buffers[1] );
-    free ( buffers[2] );
+void domain_finalize(void) {
+  free(buffers[0]);
+  free(buffers[1]);
+  free(buffers[2]);
 }
 
-
 // Rotate the time step buffers.
-void move_buffer_window ( void )
-{
-    real_t *temp = buffers[0];
-    buffers[0] = buffers[1];
-    buffers[1] = buffers[2];
-    buffers[2] = temp;
+void move_buffer_window(void) {
+  real_t *temp = buffers[0];
+  buffers[0] = buffers[1];
+  buffers[1] = buffers[2];
+  buffers[2] = temp;
 }
 
-
 // TASK: T4
 // Derive step t+1 from steps t and t-1.
-void time_step ( void )
-{
-// BEGIN: T4
-    for ( int_t i=0; i<N; i++ )
-    {
-        U_nxt(i) = -U_prv(i) + 2.0*U(i)
-                 + (dt*dt*c*c)/(dx*dx) * (U(i-1)+U(i+1)-2.0*U(i));
-    }
-// END: T4
+void time_step(void) {
+  // BEGIN: T4
+  for (int_t i = 0; i < N; i++) {
+    U_nxt(i) = -U_prv(i) + 2.0 * U(i) + (dt * dt * c * c) / (dx * dx) * (U(i - 1) + U(i + 1) - 2.0 * U(i));
+  }
+  // END: T4
 }
 
-
 // TASK: T6
 // Neumann (reflective) boundary condition.
-void boundary_condition ( void )
-{
-// BEGIN: T6
-    U(-1) = U(1);
-    U(N) = U(N-2);
-// END: T6
+void boundary_condition(void) {
+  // BEGIN: T6
+  U(-1) = U(1);
+  U(N) = U(N - 2);
+  // END: T6
 }
 
-
 // TASK: T5
 // Communicate the border between processes.
-void border_exchange( void )
-{
-// BEGIN: T5
-    ;
-// END: T5
+void border_exchange(void) {
+  // BEGIN: T5
+  ;
+  // END: T5
 }
 
-
 // TASK: T7
 // Every process needs to communicate its results
 // to root and assemble it in the root buffer
-void send_data_to_root()
-{
-// BEGIN: T7
-    ;
-// END: T7
+void send_data_to_root() {
+  // BEGIN: T7
+  ;
+  // END: T7
 }
 
-
 // Main time integration.
-void simulate( void )
-{
-    // Go through each time step.
-    for ( int_t iteration=0; iteration<=max_iteration; iteration++ )
-    {
-        if ( (iteration % snapshot_freq)==0 )
-        {
-            send_data_to_root();
-            domain_save ( iteration / snapshot_freq );
-        }
-
-        // Derive step t+1 from steps t and t-1.
-        border_exchange();
-        boundary_condition();
-        time_step();
-
-        move_buffer_window();
+void simulate(void) {
+  // Go through each time step.
+  for (int_t iteration = 0; iteration <= max_iteration; iteration++) {
+    if ((iteration % snapshot_freq) == 0) {
+      send_data_to_root();
+      domain_save(iteration / snapshot_freq);
     }
+
+    // Derive step t+1 from steps t and t-1.
+    border_exchange();
+    boundary_condition();
+    time_step();
+
+    move_buffer_window();
+  }
 }
 
+int main(int argc, char **argv) {
+  // TASK: T1c
+  // Initialise MPI
+  // BEGIN: T1c
+  ;
+  // END: T1c
 
-int main ( int argc, char **argv )
-{
-// TASK: T1c
-// Initialise MPI
-// BEGIN: T1c
-    ;
-// END: T1c
-    
-    struct timeval t_start, t_end;
+  struct timeval t_start, t_end;
 
-    domain_initialize();
+  domain_initialize();
 
-// TASK: T2
-// Time your code
-// BEGIN: T2
-    simulate();
-// END: T2
-   
-    domain_finalize();
+  // TASK: T2
+  // Time your code
+  // BEGIN: T2
+  simulate();
+  // END: T2
 
-// TASK: T1d
-// Finalise MPI
-// BEGIN: T1d
-    ;
-// END: T1d
+  domain_finalize();
 
-    exit ( EXIT_SUCCESS );
+  // TASK: T1d
+  // Finalise MPI
+  // BEGIN: T1d
+  ;
+  // END: T1d
+
+  exit(EXIT_SUCCESS);
 }