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  1. #include <stdio.h>
  2. //関数のプロトタイプ宣言
  3. //ここ↓を埋めてね1
  4. void goldbach(int n);
  5. void print(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. 	//ここを埋めてね2
  21. 	for(int x=2;x<=n/2;x++){
  22. 		if(prime(x)==1&&prime(n-x)==1){
  23. 			print(x,n-x);
  24. 		}
  25. 	}
  26.  
  27.  
  28.  
  29. }
  30.  
  31. //結果表示
  32. void print(int a, int b){
  33. 	//ここ↓を埋めてね3
  34. 	static int count=1;
  35.  
  36.     printf("%2d: %d = %d + %d\n", count, a+b, a,b);
  37.     count++;
  38. }
  39.  
  40. //素数判定
  41. int prime(int n){
  42.     int i;
  43.     int sosuu = 1;
  44.  
  45.     for(i=2; i<n; i++){
  46.         if(n%i==0){
  47.             sosuu = 0;
  48.             break;
  49.         }
  50.     }
  51.     return sosuu;
  52. }
Success #stdin #stdout 0.01s 5320KB
comments (?)
stdin
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24
stdout
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 1: 24 = 5 + 19
 2: 24 = 7 + 17
 3: 24 = 11 + 13
https://ideone.com/XCYWuj
language:
C (gcc 8.3)
created:
6 days ago
visibility:
public

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