122-Triangular Sums 内存限制:64MB 时间限制:3000ms 特判: No 通过数:5 提交数:7 难度:2 题目描述: The nth Triangular number, T(n) = 1 + … + n, is the sum of the first n integers. It is the number of points in a triangular array with n points on side. For example T(4): X X X X…