fork download
copy 
  1. #include <stdio.h>
  2.  
  3. #define  N  100
  4.  
  5. int main(void)
  6. {
  7.    int a[N], *p;
  8.    int i, sum = 0;
  9.  
  10.    printf("p = %d, &a[0] = %d, &a[1] = %d and &a[99] = %d\n",
  11.            p, &a[0], &a[1], &a[99]);
  12.  
  13.    p = a;
  14.    printf("p = %d and &a[0] = %d\n", p, &a[0]);
  15.  
  16.    p = &a[0];
  17.    printf("p = %d and &a[0] = %d\n", p, &a[0]);
  18.  
  19.    p = a + 1;
  20.    printf("p = a+1 = %d and &a[0] = %d, &a[1] = %d\n", p, &a[0], &a[1]);
  21.  
  22.  
  23.    for (i = 0; i < N; ++i)  /* initialize the array */
  24.       a[i] = i + 1;
  25.  
  26.    for (p = a; p < &a[N]; ++p) /* compute first sum */
  27.       sum += *p;
  28.    printf("first sum = %d\n", sum);
  29.  
  30.    sum = 0;
  31.    for (i = 0; i < N; ++i)  /* compute second sum */
  32.       sum += *(a + i); /* (a+i) is the ith offset from the base address of a */
  33.    printf("second sum = %d\n", sum);
  34.  
  35.    p = a;
  36.    sum = 0;
  37.    for (i = 0; i < N; ++i)  /* compute third sum */
  38.       sum += p[i];  /* p[i] is equivalent to *(p+i) */
  39.    printf("third sum = %d\n", sum);
  40.  
  41.  
  42.     sum = 0;
  43.    for (i = 0; i < N; ++i)  /* compute third sum */
  44.       sum += *(p+i);  /* p[i] is equivalent to *(p+i) */
  45.    printf("fourth sum = %d\n", sum);
  46.  
  47.  
  48.  
  49.    return 0;
  50. }
  51.  
  52.  
Success #stdin #stdout 0s 2168KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
p = 0, &a[0] = -4383648, &a[1] = -4383644 and &a[99] = -4383252
p = -4383648 and &a[0] = -4383648
p = -4383648 and &a[0] = -4383648
p = a+1 = -4383644 and &a[0] = -4383648, &a[1] = -4383644
first sum = 5050
second sum = 5050
third sum = 5050
fourth sum = 5050
https://ideone.com/4H1BMc
language:
C (gcc 8.3)
created:
7 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!