LeetCode 118 Pascal's Triangle

Problem:

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] ]

Summary:

输出杨辉三角的前n行。

Solution:

方法类似于LeetCode 119 Pascal's Triangle II

1 class Solution { 2 public: 3 vector<vector<int>> generate(int numRows) { 4 vector<vector<int>> res; 5 vector<int> v; 6 for (int i = 0; i < numRows; i++) { 7 v.resize(i + 1); 8 v[0] = v[i] = 1; 9 for (int j = i - 1; j > 0; j--) { 10 v[j] = v[j - 1] + v[j]; 11 } 12 res.push_back(v); 13 } 14 15 return res; 16 } 17 };

class Solution {public:    vector<vector<int>> generate(int numRows) {        vector<vector<int>> res;        vector<int> v;        for (int i = 0; i < numRows; i++) {            v.resize(i + 1);            v[0] = v[i] = 1;            for (int j = i - 1; j > 0; j--) {                v[j] = v[j - 1] + v[j];            }            res.push_back(v);        }                return res;    }};

转载于:https://www.cnblogs.com/VickyWang/p/6231476.html