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-rw-r--r--p357/src/erasto.c30
-rw-r--r--p357/src/main.rs52
2 files changed, 82 insertions, 0 deletions
diff --git a/p357/src/erasto.c b/p357/src/erasto.c
new file mode 100644
index 0000000..d11b52e
--- /dev/null
+++ b/p357/src/erasto.c
@@ -0,0 +1,30 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+
+const MAX_PRIMES = 100010000;
+const SQRT_MAX_PRIMES = 10000;
+
+int main(int argc, char* argv[]) {
+ bool* primes = calloc(MAX_PRIMES, sizeof(bool));
+ memset(primes, true, MAX_PRIMES);
+
+
+ primes[0] = false;
+ primes[1] = false;
+
+ for( int i = 2 ; i < SQRT_MAX_PRIMES ; i++) {
+ if(primes[i]) {
+ for( int j = i*i ; j < MAX_PRIMES ; j+=i) {
+ primes[j] = false;
+ }
+ }
+ }
+
+ size_t cnt = 0;
+ for( int i = 0 ; i < MAX_PRIMES ; i++)
+ if(primes[i]) cnt++;
+ printf("Count is : %zu\n", cnt);
+}
+
diff --git a/p357/src/main.rs b/p357/src/main.rs
new file mode 100644
index 0000000..14a5d02
--- /dev/null
+++ b/p357/src/main.rs
@@ -0,0 +1,52 @@
+const MAX_PRIMES: usize = 200_000_000;
+const MAX_DIV_PRIMES: usize = 100_000_000;
+const SQRT_MAX_PRIMES: usize = 14_142;
+
+fn main() {
+ let mut primes = vec![true;MAX_PRIMES];
+
+ primes[0] = false;
+ primes[1] = false;
+
+ for i in 2..SQRT_MAX_PRIMES {
+ if primes[i] {
+ let mut j = i*i;
+ while j < MAX_PRIMES {
+ primes[j] = false;
+ j += i;
+ }
+ }
+ }
+
+ let mut cnt = 0;
+ for i in &primes {
+ if *i {
+ cnt += 1;
+ }
+ }
+ println!("Count is {}", cnt);
+
+ let mut sum: u64 = 0;
+ for i in 1..MAX_DIV_PRIMES {
+ if primes[i+1] {
+ let mut ok = true;
+
+ let mut j = 1;
+ while j*j <= i {
+ if i % j == 0 {
+ if !primes[j + i/j] {
+ ok = false;
+ break;
+ }
+ }
+ j += 1;
+ }
+ if ok {
+ sum += i as u64;
+ }
+ }
+ }
+ println!("Sum is {}", sum);
+
+
+}