leetcode-560 - Subarray Sum Equals K

動機 我忘了prefix sum!! 同時,這題不能用sliding window ...

July 20, 2021 · 2 min · zhengcf

leetcode-523 - Continuous Subarray Sum

動機 要與560一起看 ...

January 31, 2021 · 2 min · zhengcf

leetcode-304 - Range Sum Query 2D - Immutable

動機 就是一維的推廣 ...

November 3, 2020 · 3 min · zhengcf