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authormjfernez <mjfernez@gmail.com>2020-02-03 23:04:10 -0500
committermjfernez <mjfernez@gmail.com>2020-02-03 23:04:10 -0500
commit8e431d287c0e89041506da4c4da57e3e3d657d72 (patch)
treeb6cd296fbdd75d1421fe84a82cf3eec859407dcb /10001prime.c
parente6a7399134b3dc08f9e6e9c9c74e39ac449b8538 (diff)
downloadProject_Euler_Solutions-8e431d287c0e89041506da4c4da57e3e3d657d72.tar.gz
cleanup, added c translations for some
Diffstat (limited to '10001prime.c')
-rw-r--r--10001prime.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/10001prime.c b/10001prime.c
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index 0000000..2ef3bd8
--- /dev/null
+++ b/10001prime.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+int n = 1000000;
+
+int *listPrimes(int num){
+ int i;
+ int *primes;
+ int *sieve = (int *) malloc(num * sizeof(int));
+ //initialize to all 1s (except 0 and 1 which are not prime)
+ for(i = 2; i < num; i++)
+ sieve[i] = 1;
+ for(i = 2; i < ceil(sqrt(num)); i++){
+ if(sieve[i] == 1){
+ int j = i * i;
+ while(j < num){
+ sieve[j] = 0;
+ j += i;
+ }
+ }
+ }
+
+ //now check which were prime
+ int s = 0;
+ primes = (int *) malloc(sizeof(int));
+ for(i = 2; i < num; i++){
+ if(sieve[i]){
+ primes[s] = i;
+ s++;
+ primes = (int *) realloc (primes, (s + 1) * sizeof(int));
+ }
+ }
+
+ return primes;
+}
+
+int main(){
+ int *p = listPrimes(n);
+ int prime10001 = p[10000];
+ printf("%d\n", prime10001);
+ return 0;
+}