Solved 0118

Author: guangsheng.li01

src/a0118_pascals_triangle.rs

@@ -0,0 +1,53 @@
+/*
+ * [0118] pascals-triangle
+ */
+
+pub struct Solution {}
+
+// solution impl starts here
+
+impl Solution {
+    pub fn generate(num_rows: i32) -> Vec<Vec<i32>> {
+        let mut t = Vec::with_capacity(num_rows as usize);
+        for i in 0..num_rows as usize {
+            let mut v: Vec<i32> = (0..i + 1).map(|_| 1).collect();
+            if i > 0 {
+                for j in 1..i {
+                    let last_row: &Vec<i32> = &t[i - 1];
+                    v[j] = last_row[j - 1] + last_row[j];
+                }
+            }
+            t.push(v);
+        }
+        t
+    }
+}
+
+// solution impl ends here
+
+// solution tests starts here
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_case0() {
+        assert_eq!(Solution::generate(1), vec![vec![1]]);
+    }
+
+    #[test]
+    fn test_case1() {
+        assert_eq!(Solution::generate(2), vec![vec![1], vec![1, 1]]);
+    }
+
+    #[test]
+    fn test_case2() {
+        assert_eq!(
+            Solution::generate(3),
+            vec![vec![1], vec![1, 1], vec![1, 2, 1]]
+        );
+    }
+}
+
+// solution tests ends here

src/lib.rs

@@ -13,6 +13,7 @@ mod a0035_search_insert_position;
 mod a0053_maximum_subarray;
 mod a0066_plus_one;
 mod a0088_merge_sorted_array;
+mod a0118_pascals_triangle;
 mod a0145_binary_tree_postorder_traversal;
 mod a0172_factorial_trailing_zeroes;
 mod a0400_nth_digit;