From: http://www.geeksforgeeks.org/find-number-of-triangles-possible/ Given an unsorted array of positive integers. Find the number of triangles that can be formed with three different array elements as three sides of triangles. For a triangle to be…

Description It is always very nice to have little brothers or sisters. You can tease them, lock them in the bathroom or put red hot chili in their sandwiches. But there is also a time when all meanness comes back! As you know, in one month it is Chri…

Triangles Time Limit:1000MS     Memory Limit:64000KB     64bit IO Format:%lld & %llu Submit Status Practice ACdream 1067 Description 已知一个圆的圆周被  N 个点分成了 N 段等长圆弧,求任意取三个点,组成锐角三角形的个数. Input 多组数据. 每组数据一个N (N ≤  1000000). Output 对于每组数据,输出不同锐角三角形的个数. Sample…

You will be given N points on a circle. You must write a program to determine how many distinctequilateral triangles can be constructed using the given points as vertices.The gure below illustrates an example: (a) shows a set of points, determined by…

Fighting for Triangles 题目连接: http://codeforces.com/gym/100015/attachments Description Andy and Ralph are playing a two-player game on a triangular board that looks like the following: 1 2 3 4 5 7 8 6 9 10 11 13 14 16 17 12 15 18 At each turn, a playe…

C. Love Triangles Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/553/problem/C Description There are many anime that are about "love triangles": Alice loves Bob, and Charlie loves Bob as well, but Alice hates Charlie.…

D. Vanya and Triangles Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/552/problem/D Description Vanya got bored and he painted n distinct points on the plane. After that he connected all the points pairwise and saw that as…

Almost equilateral triangles It is easily proved that no equilateral triangle exists with integral length sides and integral area. However, the almost equilateral triangle 5-5-6 has an area of 12 square units. We shall define an almost equilateral tr…

Right triangles with integer coordinates The points P (x1, y1) and Q (x2, y2) are plotted at integer co-ordinates and are joined to the origin, O(0,0), to form ΔOPQ. There are exactly fourteen triangles containing a right angle that can be formed whe…

题目链接 原题: It turns out that 12 cm is the smallest length of wire that can be bent to form an integer sided right angle triangle in exactly one way, but there are many more examples. 12 cm: (3,4,5)24 cm: (6,8,10)30 cm: (5,12,13)36 cm: (9,12,15)40 cm: (…