118. 杨辉三角

src/main.rs

@@ -1,19 +1,21 @@
-use std::cmp::max;
-
 struct Solution;
 impl Solution {
-    pub fn does_valid_array_exist(derived: Vec<i32>) -> bool {
-        let mut a = 0;
-        let mut b = 1;
-        for i in derived.iter() {
-            a ^= i;
-            b ^= i;
+    pub fn generate(num_rows: i32) -> Vec<Vec<i32>> {
+        let mut ans : Vec<Vec<i32>>= vec![vec![1]];
+        for i in 1..num_rows {
+            let mut row = vec![1];
+            let prev_row = &ans[(i - 1) as usize];
+            for j in 1..prev_row.len() {
+                row.push(prev_row[j - 1] + prev_row[j]);
+            }
+            row.push(1);
+            ans.push(row);
         }
-        a == 0 || b == 1
+        ans
     }
 }
 
 fn main() {
-    let sl = Solution::does_valid_array_exist(vec![1,1,0]);
+    let sl = Solution::generate(7);
     println!("{:?}", sl);
 }