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  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #define N 46340
  4. char table[N]={0};
  5. int main(int argc, char *argv[])
  6. {
  7.   int i,j;
  8.   for(i=2;i<N;i++){
  9.       if(table[i]==1)continue;
  10.       for(j=i+i;j<N;j+=i){
  11.           table[j]=1;                    
  12.       }                 
  13.   }
  14.   int x;
  15.   while(scanf("%d",&x)==1){
  16.       if(x<N){
  17.           if(table[x]){
  18.               printf("非質數\n");             
  19.           }else{
  20.               printf("質數\n");      
  21.           }
  22.           continue;        
  23.       }
  24.       for(i=2;;i++){
  25.           if(i*i>x){
  26.               printf("質數\n");
  27.               break;          
  28.           }
  29.           if(table[i]==0&&x%i==0){
  30.               printf("非質數\n");
  31.               break;  
  32.           }                                  
  33.       }                 
  34.   }  
  35.   return 0;
  36. }
  37.  
Success #stdin #stdout 0s 2340KB
comments (?)
stdin
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20
800
99990001
99990003
stdout
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非質數
非質數
質數
非質數
https://ideone.com/Lu5l3K
language:
C (gcc 8.3)
created:
11 years ago
visibility:
public

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