Hi everyone. Today i meet a problem like that: There are n cities, and each city i has a height h_i and a rental cost p_i for using a flying vehicle. To travel from city i to city j, the cost is defined as: cost(i, j) = max(p_i, h_j — h_i).

A tourist wants to start from city 1, visit all cities exactly once, and finally return to city 1, using the flying vehicle. Your task is to determine the minimum total travel cost.

Input: • The first line contains an integer n (1 ≤ n ≤ 10⁵) — the number of cities. • Each of the next n lines contains two integers h_i and p_i (0 ≤ h_i, p_i ≤ 10⁹) — the height and the rental cost of city i.

Output: • Output a single integer — the minimum total cost to visit all cities exactly once, starting and ending at city 1.

I think it maybe a dp problem. I guess suppose you have solution for n-1, if you add n to path, it will add destroy the structure of the path in n-1 before. Example if you have 1-3-5-4-2-1 is the answer of n=5, if you add 6 to the path 6 may be between 1,3 or 3,5 or 5,4 ... Is it right solution or someone has others answer. Thank you for your help.

Hi guys. To day i meet a problem that : give you integer t is number of test case (t <= 10) each line have an interger n ( n <= 1e6) , Count the number of ways to choose a distinct (at least 1) set of numbers (elements in the ascending set) such that they form an arithmetic progression.

example : if n = 3 , the answer is 7 : (1,2,3,12,13,23,123)

Hi everyone. i have to solve a problem like that finding the last three digits before the decimal point for the number (3+sqrt(5))^n with n <= 2e9. I thinked but don't have the idea about this problem. So thank you if you help me to solve and i want to know that if with anyone number such is not integer number. can i finding the last three digits before the decimal point. Very thank you