vault backup: 2022-06-28 09:31:37

CS notes/pages/Leetcode Pascal's-Triangle.md

@@ -56,7 +56,6 @@ Output: [[1]]
 Very simple and straightforward problem.
 > [!summary]
 > answer[i][j] = answer[i - 1][j - 1] + answer[i - 1][j]
-> except for special cases: i <= 1 etc.
 
 I worked around special cases using the for loop in j: j = 1 and j < i.
 
@@ -66,18 +65,16 @@ class Solution {
 public:
   vector<vector<int>> generate(int numRows) {
     vector<vector<int>> answer(numRows);
-      int sum;
-      // Initialize vector
-      answer[0] = vector<int> (1);
-      answer[0][0] = 1;
-      for (int i = 1; i < numRows; i++) {
-        // initialize sub vector
-        answer[i] = vector<int> (i + 1);
+
+    for (int i = 0; i < numRows; i++) {
+      // initialize sub-array
+      answer[i] = vector<int>(i + 1);
+
       answer[i][0] = 1;
-        answer[i][i] = 1;
       for (int j = 1; j < i; j++) {
         answer[i][j] = answer[i - 1][j] + answer[i - 1][j - 1];
       }
+      answer[i][i] = 1;
     }
     return answer;
   }