輸入格式:
輸入在一行給出正整數N
。
輸出格式:
在一行中輸出不超過N
的滿足猜想的素數對的個數。
輸入樣例:
20
輸出樣例:
4
代碼:
#include <stdio.h>
#include <math.h>
int checkPrime(int number);
int main(int argc, char *argv) {
int number;
int i;
scanf("%d", &number);
int array[10000];
int index = 0;
int sum = 0;
int *zero;
for( i = 2; i <= number; i++) {
if (checkPrime(i)) {
array[index] = i;
index++;
}
}
zero = array;
int location = 0;
for (location = 0; location < index+1; location++) {
if(*(zero + location + 1) - *(zero + location) == 2) {
sum++;
}
}
printf("%d", sum);
return 0;
}
int checkPrime(int number) {
int i = 2, result = 1;
for (i; i <= sqrt(number); i++) {
if (number % i == 0) {
result = 0;
break;
}
}
return result;
}
結果: