程式語言 - LeetCode - C++ - 119. Pascal's Triangle II



題目:


方法:

從右往左更新,避免更新到舊的
row[j] = row[j] + row[j - 1]

解答:

class Solution {
public:
    vector<int> getRow(int rowIndex) {
        vector<int> ans(rowIndex + 1, 1);

        for (int i = 2; i <= rowIndex; ++i) {
            for (int j = i - 1; j > 0; --j) {
                ans[j] += ans[j - 1];
            }
        }

        return ans;
    }
};