#include<stdio.h>
#include<math.h>
#include<stdbool.h>
//exclude N
#define E 0
//include N
#define Id 1
int countPrime;
int *primes;
int *addends;
int N;
int S;
/**
* Determine whether it is prime
* @param prime
*/
bool isPrime(int prime){
int k = (int)sqrt((double)prime);
for(int i = 2; i <= k; i++){
if(prime % i == 0)
return false;
}
return true;
}
/**
* Initial Prime
* @param N Number of addends
* @param S sum
* @param coutPrime_ Number of Primes
*/
int *getPrime(int *N, int *S, int *coutPrime_){
//Initial Prime
int P;
printf("please input N,prime P, S:\n");
scanf("%d,%d,%d" , N, &P, S);
int *primes_ = malloc(sizeof(int) * (*S - P));
int countPrime = 0;
for(int i = 0; i < *S - P; i++){
int digit = *S - P - i;
if(isPrime(digit) && digit > P)
primes_[countPrime++] = digit;
}
*coutPrime_ = countPrime;
if(countPrime == 0){
free(primes_);
return NULL;
}
int *primes = malloc(sizeof(int) * countPrime);
printf("The follows is prime:\n");
for(int i = 0; i < countPrime; i++){
primes[i] = primes_[i];
printf("%5d",primes[i]);
}
printf("\n");
free(primes_);
return primes;
}
/**
* Prime numbers after prime P with sum S
* @param
*/
void printAddends(){
for(int i = 0; i < countPrime; i++){
if(addends[i] == Id)
printf("%5d", primes[i]);
}
printf("\n");
}
/**
* summed of all addends
* @param
*/
bool sumPrimes(){
int sum = 0;
int count = 0;
for(int i = 0; i < countPrime; i++){
if(addends[i] == Id){
sum += primes[i];
count++;
}
}
if(count == N && sum == S)
return true;
return false;
}
/**
* Prime numbers after prime P with sum S
* @param index
*/
void primeSum(int index){
if(index == countPrime){
if(sumPrimes())
printAddends();
return ;
}
addends[index] = E;
primeSum(index + 1);
addends[index] = Id;
primeSum(index + 1);
}
int main(){
primes = getPrime(&N, &S, &countPrime);
addends = calloc(countPrime, sizeof(int));
// addends = malloc(countPrime * sizeof(int));
printf("The follows is summarize:\n");
primeSum(0);
free(primes);
free(addends);
return 0;
}