2044. 统计按位或能得到最大值的子集数目

src/main.rs

@@ -1,25 +1,19 @@
 struct Solution;
 impl Solution {
-    pub fn max_sum(mut nums: Vec<i32>) -> i32 {
-        nums.sort_by(|a,b| b.cmp(a));
-        let mut last = nums[0];
-        let mut ans = nums[0];
-        for i in 1..nums.len() {
-            let t = nums[i];
-            if t <= 0 {
-                break
+    pub fn count_max_or_subsets(nums: Vec<i32>) -> i32 {
+        let max_or = nums.iter().fold(0, |acc, &x| acc | x);
+        let mut dp = vec![0;1<<nums.len()];
+        for i in 0..nums.len() {
+            for j in (1<<i)..(1<<(i+1)) {
+                dp[j] = dp[j - (1<<i)] | nums[i];
             }
-            if t == last {
-                continue;
         }
-            last = t;
-            ans += t;
-        }
-        ans
+        dp.iter().filter(|x| **x == max_or ).count() as i32
     }
 }
 
 fn main() {
-    let sl = Solution::max_sum(vec![-1,-2]);
+    let sl = Solution::count_max_or_subsets(vec![3,2,1,5]);
     println!("{}", sl);
 }
+