Pascal'sTriangle

Change-Id: I205969737b5316955a2c4c79420e9588f4b1650d

Author: applewjg

Pascal'sTriangle.java

@@ -0,0 +1,39 @@
+/*
+ Author:     Andy, nkuwjg@gmail.com
+ Date:       Apr 16, 2013
+ Problem:    Pascal's Triangle
+ Difficulty: Easy
+ Source:     http://leetcode.com/onlinejudge#question_118
+ Notes:
+ Given numRows, generate the first numRows of Pascal's triangle.
+ For example, given numRows = 5,
+ Return
+ [
+      [1],
+     [1,1],
+    [1,2,1],
+   [1,3,3,1],
+  [1,4,6,4,1]
+ ]
+
+ Solution: .....
+ */
+public class Solution {
+    public List<List<Integer>> generate(int numRows) {
+        List<List<Integer>> res = new ArrayList<List<Integer>>();
+        if (numRows < 1) return res;
+        List<Integer> temp = new ArrayList<Integer>();
+        temp.add(1);
+        res.add(temp);
+        for (int i = 1; i < numRows; ++i) {
+            List<Integer> t = new ArrayList<Integer>();
+            t.add(1); 
+            for (int j = 1; j < i; ++j) {
+                t.add(res.get(i-1).get(j-1) + res.get(i-1).get(j));
+            }
+            t.add(1);
+            res.add(t);
+        }
+        return res;
+    }
+}