maximum-erasure-value

first-missing-positive/sol.rs

@@ -1,20 +1,37 @@
-// TODO: Incomplete
 struct Solution {}
+
+// TODO: Incomplete
 impl Solution {
     pub fn first_missing_positive(nums: Vec<i32>) -> i32 {
-        let (max, sum) = nums
+        let (count, max, sum) = nums
             .iter()
-            .fold((0, 0), |(max, sum), n| {
+            .fold((0, 0, 0), |(count, max, sum), n| {
                 if *n > 0 {
-                    return (if *n > max { *n } else { max }, sum + *n);
+                    return (count + 1, if *n > max { *n } else { max }, sum + *n);
                 }
-                (max, sum)
+                (count, max, sum)
             });
-        let missing = max * (max + 1) / 2 - sum;
-        return if missing == 0 { max + 1 } else { missing };
+        let expected_sum = max * (max + 1) / 2;
+        let missing = max - count;
+        let diff = expected_sum - sum;
+        if diff == 0 {
+            max + 1
+        } else if missing == 1 {
+            diff
+        } else {
+            let min_k = missing * (missing - 1) / 2;
+            (1..).find(|&n| {
+                let k = diff - n * missing;
+                k >= min_k && n + k - min_k + missing <= max
+            }).unwrap()
+        }
     }
 }
 
 fn main() {
-    println!("{}", Solution::first_missing_positive(vec![99,94,96,11,92,5,91,89,57,85,66,63,84,81,79,61,74,78,77,30,64,13,58,18,70,69,51,12,32,34,9,43,39,8,1,38,49,27,21,45,47,44,53,52,48,19,50,59,3,40,31,82,23,56,37,41,16,28,22,33,65,42,54,20,29,25,10,26,4,60,67,83,62,71,24,35,72,55,75,0,2,46,15,80,6,36,14,73,76,86,88,7,17,87,68,90,95,93,97,98]));
+    println!("{}", Solution::first_missing_positive(vec![7,9,10])); // n = 1, m = 7, k = 22
+    println!("{}", Solution::first_missing_positive(vec![6,5,-1,2,4,3,1])); // n = 7, m = 1, k = 0
+    println!("{}", Solution::first_missing_positive(vec![4,-1,1])); // n = 2, m = 2, k = 1
+    println!("{}", Solution::first_missing_positive(vec![4,6,-1,1])); // n = 2, m = 3, k = 4
+    println!("{}", Solution::first_missing_positive(vec![2,2])); // n = 2, m = 3, k = 4
 }

maximum-erasure-value/sol.rs

@@ -0,0 +1,20 @@
+use std::collections::HashSet;
+
+impl Solution {
+    pub fn maximum_unique_subarray(nums: Vec<i32>) -> i32 {
+        let mut l = 0;
+        let mut max = 0;
+        let mut sum = 0;
+        let mut exists = HashSet::new();
+        for r in 0..nums.len() {
+            sum += nums[r];
+            while !exists.insert(nums[r]) {
+                exists.remove(&nums[l]);
+                sum -= nums[l];
+                l += 1;
+            }
+            max = max.max(sum);
+        }
+        max as i32
+    }
+}