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  1. #include <stdio.h>
  2.  
  3. //関数のプロトタイプ宣言
  4. void goldbach(int n);
  5. void q(int a, int b);
  6. int prime(int n);
  7.  
  8. //main関数
  9. int main(void){
  10.     int a;
  11.  
  12.     scanf("%d", &a);
  13.     goldbach(a);    
  14.  
  15.     return 0;
  16. }
  17.  
  18. // ゴールドバッハ予想
  19. void goldbach(int n){
  20.     int i;
  21.     int count = 0;
  22.     for(i=2; i<n; i++){
  23.         if(prime(i) && prime(n-i)){
  24.             count++;
  25.             q(i, n-i);
  26.         }
  27.     }
  28. }
  29.  
  30. //結果表示
  31. void q(int a, int b){
  32.     static int count = 0;  // 呼ばれtabi値が保持
  33.     count++;
  34.     printf("%2d: %d = %d + %d\n", count, a+b, a, b);
  35. }
  36.  
  37. //素数判定
  38. int prime(int n){
  39.     int i;
  40.     int sosuu = 1;
  41.  
  42.     for(i=2; i<n; i++){
  43.         if(n%i==0){
  44.             sosuu = 0;
  45.             break;
  46.         }
  47.     }
  48.     return sosuu;
  49. }
  50.  
  51.  
Success #stdin #stdout 0.01s 5316KB
comments (?)
stdin
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24
stdout
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 1: 24 = 5 + 19
 2: 24 = 7 + 17
 3: 24 = 11 + 13
 4: 24 = 13 + 11
 5: 24 = 17 + 7
 6: 24 = 19 + 5
 7: 24 = 23 + 1
https://ideone.com/jbflyd
language:
C (gcc 8.3)
created:
11 days ago
visibility:
public

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