feat: 812_largest_triangle_area

812_largest_triangle_area/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "largest_triangle_area"
+version = "0.1.0"

812_largest_triangle_area/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "largest_triangle_area"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

812_largest_triangle_area/src/lib.rs

@@ -0,0 +1,34 @@
+pub struct Solution;
+
+impl Solution {
+    pub fn largest_triangle_area(points: Vec<Vec<i32>>) -> f64 {
+        let mut result = 0.0_f64;
+
+        for (a_index, a) in points.iter().enumerate() {
+            for (b_index, b) in points.iter().enumerate().skip(a_index + 1) {
+                for c in points.iter().skip(b_index + 1) {
+                    let area = Solution::area((a[0], a[1]), (b[0], b[1]), (c[0], c[1]));
+                    if area.is_nan() {
+                        continue;
+                    }
+                    result = result.max(area);
+                }
+            }
+        }
+
+        result
+    }
+
+    fn distance(a: (i32, i32), b: (i32, i32)) -> f64 {
+        ((a.0 - b.0).pow(2) as f64 + (a.1 - b.1).pow(2) as f64).sqrt()
+    }
+
+    fn area(a: (i32, i32), b: (i32, i32), c: (i32, i32)) -> f64 {
+        let ab = Solution::distance(a, b);
+        let bc = Solution::distance(b, c);
+        let ac = Solution::distance(a, c);
+        let s = (ab + bc + ac) / 2.0;
+
+        (s * (s - ab) * (s - bc) * (s - ac)).sqrt()
+    }
+}