목표

codeforces의 최근 contest에서
등급이 올라간 유저와 등급이 내려간 유저들을 구해봅니다.

사용한 api

1. contest.list

   최근 컨테스트들의 아이디를 얻습니다.

2. contest.ratingChanges

   컨테스트 아이디로 레이팅의 변화를 살펴보고 간단히 처리합니다.

script

아래 파이썬 스크립트를 실행하면 이번 컨테스트에서 강등/승급한 사람이 몇 명인지 보여줍니다.

import requests
import time
#import datetime
#import json



# codeforces의  가장 최근 콘테스트에서,
# 승급한 사람과 강등당한 사람을 구해봅니다.

URL='https://codeforces.com/api/'
method1='contest.list'
payload={'gym':'false'}
URI=URL+method1
response=requests.get(URI,payload)
print(response.status_code)     #succeeded?
result=response.json()['result']
#print(result)
ContestName={}
#print("time now : ",datetime.datetime.now())
print("time now:",time.time())
nowtime=time.time()

for res in result:
    #ContestId[res['name']]=res['id']
    ContestName[res['id']]=res['name']

cnt=0
RecentContestId=[]
for res in result:
    if res['startTimeSeconds']>=nowtime:        #not yet started contests -> skip
        continue
    if cnt>=30:
        break
    RecentContestId.append(res['id'])
    cnt+=1

# < show all Contest's name,Id>
# for name,id in ContestId.items():
#    print(name,id)

########################################################################

#RatingChange
#Represents a participation of user in rated contest.

ratings={}
for i in range(-1000,4000):
    if i<1200:
        ratings[i]='newbie'
        continue

    if i<1400:
        ratings[i]='pupil'
        continue

    if i<1600:
        ratings[i] = 'specialist'
        continue
    if i < 1900:
        ratings[i] = 'expert'
        continue
    if i < 2100:
        ratings[i] = 'candidate master'
        continue
    if i < 2300:
        ratings[i] = 'master'
        continue
    if i < 2400:
        ratings[i] = 'International master'
        continue
    if i < 2600:
        ratings[i] = 'Grandmaster'
        continue

    if i < 3000:
        ratings[i] = 'International Grandmaster'
        continue

    ratings[i]='Legandary Grandmaster'


method2 = 'contest.ratingChanges'

for Id in RecentContestId[:1]:  #가장 최근 콘테스트만 살펴보았습니다.
    URI=URL+method2
    payload={'contestId':Id}
    response=requests.get(URI,payload)
    print(response.status_code)     #succeeded?
    result=response.json()['result']
    #print(result)
    #print(type(result))

    userInfos = []

    Sames=[]
    Changed = []
    Ups = []
    Downs = []

    for res in result:
        #print(res)
        userInfo=[]
        userInfo.append(res['handle'])
        userInfo.append(res['oldRating'])
        userInfo.append(res['newRating'])
        userInfos.append(userInfo)
        # if res['oldRating']<0 or res['newRating']>4000:       #there exists negative rated user!
        #     print(res)

    #print(userInfos)
    specialist_up=0
    specialist_down=0
    experts_up=0
    experts_down=0

    for user in userInfos:
        if ratings[user[1]] !=ratings[user[2]]:
            Changed.append(user)
            if user[1] > user[2]:     # rated down
                tmp=[]
                tmp.append(user[0])
                tmp.append(ratings[user[1]])
                tmp.append(ratings[user[2]])
                Downs.append(tmp)
                if tmp[2]=='expert':
                    experts_down+=1

                if tmp[2]=='specialist':
                    specialist_down+=1

            else:           #rated up
                tmp = []
                tmp.append(user[0])
                tmp.append(ratings[user[1]])
                tmp.append(ratings[user[2]])
                Ups.append(tmp)
                if tmp[2]=='expert':
                    experts_up+=1
                if tmp[2] == 'specialist':
                    specialist_up += 1
        else:
            Sames.append(user)


    print("Contest : ",ContestName[Id])
    print("same", len(Sames))
    print("changed",len(Changed))
    print("ups",len(Ups))
    print("downs",len(Downs))

    #이번 콘테스트에서 expert가 된 사람들.
    print("became expert (by rated up):",experts_up)
    print("became expert (by rated down):", experts_down)

    # 이번 콘테스트에서 specialist가 된 사람들.
    print("became specialist (by rated up):", specialist_up)
    print("became specialist (by rated down):", specialist_down)

낮은 구간에선 올라가는 사람들이 더 많습니다.