From 493b9c50c561811772a0dc09b5085ba7e51b770a Mon Sep 17 00:00:00 2001
From: SquidSpirit <squid@squidspirit.com>
Date: Thu, 25 Sep 2025 21:23:26 +0800
Subject: [PATCH] feat: 120_triangle

---
 120_triangle/Cargo.lock |  7 +++++++
 120_triangle/Cargo.toml |  6 ++++++
 120_triangle/src/lib.rs | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+)
 create mode 100644 120_triangle/Cargo.lock
 create mode 100644 120_triangle/Cargo.toml
 create mode 100644 120_triangle/src/lib.rs

diff --git a/120_triangle/Cargo.lock b/120_triangle/Cargo.lock
new file mode 100644
index 0000000..36179cd
--- /dev/null
+++ b/120_triangle/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "triangle"
+version = "0.1.0"
diff --git a/120_triangle/Cargo.toml b/120_triangle/Cargo.toml
new file mode 100644
index 0000000..dc19926
--- /dev/null
+++ b/120_triangle/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "triangle"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/120_triangle/src/lib.rs b/120_triangle/src/lib.rs
new file mode 100644
index 0000000..576339c
--- /dev/null
+++ b/120_triangle/src/lib.rs
@@ -0,0 +1,37 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn minimum_total(triangle: Vec<Vec<i32>>) -> i32 {
+        let mut sums = vec![i32::MAX; triangle.len()];
+        sums[0] = triangle[0][0];
+
+        for (layer, nums) in triangle.iter().enumerate() {
+            if layer == 0 {
+                continue;
+            }
+
+            let mut current_sums = vec![];
+            for (index, num) in nums[..layer + 1].iter().enumerate() {
+                let left = if index == 0 {
+                    i32::MAX
+                } else {
+                    sums[index - 1]
+                };
+
+                let right = if index == layer {
+                    i32::MAX
+                } else {
+                    sums[index]
+                };
+
+                current_sums.push(*num + std::cmp::min(left, right));
+            }
+
+            for (index, sum) in current_sums.iter().enumerate() {
+                sums[index] = *sum;
+            }
+        }
+
+        *sums.iter().min().unwrap()
+    }
+}