greedy

better solution is to build result by adding new dishes

1402_reducing_dishes.rs

@@ -0,0 +1,21 @@
+impl Solution {
+    pub fn max_satisfaction(mut dishes: Vec<i32>) -> i32 {
+        satisfaction(dishes)
+    }
+}
+
+fn satisfaction(mut dishes: Vec<i32>) -> i32 {
+    dishes.sort();
+    let positive_sum: i32 = dishes.iter().filter(|&&n| n > 0).sum();
+    let negative: Vec<i32> = dishes.iter().filter(|&&n| n < 0).cloned().collect();
+    let mut i = 0;
+    loop {
+        let diff = negative[i..].iter().sum::<i32>().abs();
+        if  diff > positive_sum {
+            i += 1;
+        } else {
+            break;
+        }
+    }
+    dishes[i..].iter().enumerate().map(|(i, &k)| (i as i32 + 1) * k).sum()
+}