feat: better resolution

Author: jtr109

count_primes/src/lib.rs

@@ -18,26 +18,24 @@ impl Solution {
     // }
 
     pub fn count_primes(n: i32) -> i32 {
-        if n < 2 {
+        if n <= 2 {
             return 0;
         }
+
         let n = n as usize;
         let mut nums = vec![true; n];
         nums[0] = false;
         nums[1] = false;
-        for i in 2..n {
-            if i * i >= n {
-                break;
-            }
-            if !nums[i] {
-                continue;
-            }
-            for times in i..n {
-                if times * i >= n {
-                    break;
+        let mut i = 2;
+        while i * i < n {
+            if nums[i] {
+                let mut j = 2;
+                while i * j < n {
+                    nums[i * j] = false;
+                    j += 1;
                 }
-                nums[times * i] = false;
             }
+            i += 1;
         }
         nums.iter().filter(|&&x| x).count() as i32
     }