【LeetCode热题100（77/100）】杨辉三角

题目地址： 链接

思路： dp

function generate(numRows: number): number[][] {
    const dp = Array.from({length: numRows + 1}, () => new Array(numRows + 1).fill(0));
    dp[1][1] = 1;
    for(let i = 2; i <= numRows; i ++) {
        for(let j = 1; j <= i; j ++) {
            dp[i][j] = dp[i - 1][j - 1] + dp[i - 1][j];
        }
    }
    const ans: number[][] = [];
    for(let i = 1; i <= numRows; i ++) {
        let rowList = [];
        for(let j = 1; j <= i; j ++ ) {
            rowList.push(dp[i][j]);
        }
        ans.push(rowList);
    }
    return ans;
};