A. Is it rated?
Is it rated?
Here it is. The Ultimate Question of Competitive Programming, Codeforces, and Everything. And you are here to answer it.
Another Codeforces round has been conducted. No two participants have the same number of points. For each participant, from the top to the bottom of the standings, their rating before and after the round is known.
It's known that if at least one participant's rating has changed, then the round was rated for sure.
It's also known that if the round was rated and a participant with lower rating took a better place in the standings than a participant with higher rating, then at least one round participant's rating has changed.
In this problem, you should not make any other assumptions about the rating system.
Determine if the current round is rated, unrated, or it's impossible to determine whether it is rated of not.
The first line contains a single integer n (2 ≤ n ≤ 1000) — the number of round participants.
Each of the next n lines contains two integers ai and bi (1 ≤ ai, bi ≤ 4126) — the rating of the i-th participant before and after the round, respectively. The participants are listed in order from the top to the bottom of the standings.
If the round is rated for sure, print "rated". If the round is unrated for sure, print "unrated". If it's impossible to determine whether the round is rated or not, print "maybe".
6
3060 3060
2194 2194
2876 2903
2624 2624
3007 2991
2884 2884
rated
4
1500 1500
1300 1300
1200 1200
1400 1400
unrated
5
3123 3123
2777 2777
2246 2246
2246 2246
1699 1699
maybe
In the first example, the ratings of the participants in the third and fifth places have changed, therefore, the round was rated.
In the second example, no one's rating has changed, but the participant in the second place has lower rating than the participant in the fourth place. Therefore, if the round was rated, someone's rating would've changed for sure.
In the third example, no one's rating has changed, and the participants took places in non-increasing order of their rating. Therefore, it's impossible to determine whether the round is rated or not.
题目链接:http://codeforces.com/contest/807/problem/A
题意:给你n个人在一场CF前后的rating值; 问你这场比赛是不是计分的
分析:如果有一个人的rating变了; 则是计分的; 否则; 按照题目所给的规则判断是maybe还是unrated; O(N^2) ,做法先开两个数组进行比较,看是否相等,然后再进行排序,看是否存在两个非单调递减的数组,此为正解!
下面给出AC代码:
1 #include <bits/stdc++.h> 2 using namespace std; 3 int a[1010],b[1010]; 4 int main() 5 { 6 int n; 7 while(scanf("%d",&n)!=EOF) 8 { 9 int sum=0; 10 for(int i=1;i<=n;i++) 11 { 12 scanf("%d%d",&a[i],&b[i]); 13 if(a[i]==b[i]) 14 sum++; 15 } 16 if(sum!=n) 17 printf("rated\n"); 18 else 19 { 20 int ans=0; 21 for(int i=1;i<=n;i++) 22 { 23 if(a[i]>=a[i+1]) 24 ans++; 25 } 26 if(ans==n) 27 printf("maybe\n"); 28 else printf("unrated\n"); 29 } 30 } 31 return 0; 32 }