20240808 Finished

src/problem/mod.rs

@@ -197,4 +197,5 @@ mod p149_max_points_on_a_line;
 mod p70_climbing_stairs;
 mod p198_house_robber;
 mod p139_word_break;
-mod p300_longest_increasing_subsequence;
+mod p300_longest_increasing_subsequence;
+mod p120_triangle;

src/problem/p120_triangle.rs

@@ -0,0 +1,42 @@
+/**
+ * [120] Triangle
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+
+impl Solution {
+    pub fn minimum_total(triangle: Vec<Vec<i32>>) -> i32 {
+        let n = triangle.len();
+        let mut dp = vec![i32::MAX; n];
+        dp[0] = 0;
+
+        for i in 0..n {
+            let mut next_dp = vec![i32::MAX; n];
+            for j in 0..=i {
+                if j == 0 {
+                    next_dp[j] = triangle[i][j] + dp[j];
+                } else {
+                    next_dp[j] = triangle[i][j] + dp[j - 1].min(dp[j]);
+                }
+            }
+
+            dp = next_dp;
+        }
+
+        *dp.iter().min().unwrap()
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_120() {
+        assert_eq!(11, Solution::minimum_total(vec![vec![2], vec![3, 4], vec![6, 5, 7], vec![4, 1, 8, 3]]));
+    }
+}