20210203 Finished

src/problem/mod.rs

@@ -36,3 +36,4 @@ mod p2808_minimum_seconds_to_equalize_a_circular_array;
 mod p2670_find_the_distinct_difference_array;
 mod lcp24_nums_game;
 mod p1686_stone_game_vi;
+mod p1690_stone_game_vii;

src/problem/p1690_stone_game_vii.rs

@@ -0,0 +1,42 @@
+/**
+ * [1690] Stone Game VII
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+
+impl Solution {
+    pub fn stone_game_vii(stones: Vec<i32>) -> i32 {
+        let n = stones.len();
+        let mut sum = vec![0; n + 1];
+
+        for (index, value) in stones.iter().enumerate() {
+            sum[index + 1] = sum[index] + *value;
+        }
+
+        let mut dp = vec![vec![0;n];n];
+
+        for i in (0..=n-2).rev() {
+            for j in i+1..n {
+                dp[i][j] = (sum[j + 1] - sum[i + 1] - dp[i + 1][j]).max(
+                    sum[j] - sum[i] - dp[i][j - 1]
+                );
+            }
+        }
+
+        dp[0][n - 1]
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1690() {
+        assert_eq!(Solution::stone_game_vii(vec![5,3,1,4,2]), 6);
+    }
+}