Journal Archive

2022

/**
 * @param {number} numRows
 * @return {number[][]}
 */
var generate = function(numRows) {
    let pascalTri = [];
    
    for (let i = 0; i < numRows; i++) {
        pascalTri[i] = [];
        pascalTri[i][0] = 1;
        pascalTri[i][i] = 1;
        
        for (let j = 1; j < i; j++) {
            pascalTri[i][j] = pascalTri[i - 1][j] + pascalTri[i - 1][j - 1];
        }
    }
    
    return pascalTri;
};

Day 55: Solving one of LeetCode problems

118. Pascal's Triangle Difficulty - Easy

Given an integer numRows, return the first numRows of Pascal's triangle.

In Pascal's triangle, each number is the sum of the two numbers directly above it as shown:

 

Example 1:

Input: numRows = 5
Output: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]

Example 2:

Input: numRows = 1
Output: [[1]]

 

Constraints:

  • 1 <= numRows <= 30