Friends Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 163    Accepted Submission(s): 61 Problem Description There are n people and m pairs of friends. For every pair of friends, they can choo…

Solve this interesting problem Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 422    Accepted Submission(s): 98 Problem Description Have you learned something about segment tree? If not, don’t…

Problem Description As we all kown, MZL hates the endless loop deeply, and he commands you to solve this problem to end the loop. You are given an undirected graph with n vertexs and m edges. Please direct all the edges so that for every vertex in th…

Virtual Participation Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 237    Accepted Submission(s): 56 Special Judge Problem Description As we know, Rikka is poor at math. Yuta is worrying abo…

Walk Out Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 2001    Accepted Submission(s): 376 Problem Description In an n∗m maze, the right-bottom corner is the exit (position (n,m) is the exit)…

Connect the Graph Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 108    Accepted Submission(s): 36 Special Judge Problem Description Once there was a special graph. This graph had n vertices a…

Tricks Device Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 1977    Accepted Submission(s): 509 Problem Description Innocent Wu follows Dumb Zhang into a ancient tomb. Innocent Wu’s at the en…

Crazy Bobo Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 131072/65536 K (Java/Others) Total Submission(s): 1215    Accepted Submission(s): 366 Problem Description Bobo has a tree,whose vertices are conveniently labeled by 1,2,...,n.Each nod…

Fantasy magicians usually gain their ability through one of three usual methods: possessing it as an innate talent, gaining it through study and practice, or receiving it from another being, often a god, spirit, or demon of some sort. Some wizards ar…

Painter Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 895    Accepted Submission(s): 408 Problem Description Mr. Hdu is an painter, as we all know, painters need ideas to innovate , one day,…