### 1900_mashups's blog

By 1900_mashups, history, 7 months ago,

hello codeforces,

i am glad to invite you all to my practice mashups, which i am going to start from tomorrow.
it is mainly prepared for those who aspire to become masters (be it candidates, experts, div 2 guys, div 3 guys, div 4 guys, or even an inactive master). so, the mashups will have mostly 1900+ rated problems.
i will share the mashup links through the comments of this blog, so that everyone can access it.

excited to see you guys at the standings.

• +72

 » 7 months ago, # | ← Rev. 3 →   0 the upcoming practice mashup will start at Thu, 7 July 2022, 5:35 UTC.number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000 UPD: registration is open.
 » 7 months ago, # |   -26 Thanks but I am just a newbie
 » 7 months ago, # |   0 Thanks
 » 7 months ago, # |   0 Thanks
 » 7 months ago, # | ← Rev. 3 →   0 the second practice mashup will start on 8 July 2022 at 5:35 UTC.number of problems: 3duration of mashup: 2:30 hrsrating of problems: 800, 1900, 2000UPD: registration is open.
 » 7 months ago, # | ← Rev. 2 →   0 the third practice mashup will start on 8th July 2022, today at 10:35 UTC.number of problems: 3duration of mashup: 1:30 hrsratings of problems: 800, 1600, 1900registration is open.
•  » » 7 months ago, # ^ |   0 So are you just picking any problem of given difficulty or hand-picking problems?
•  » » » 7 months ago, # ^ |   0 I am using this: https://randommashupgenerator.netlify.app/ to pick up random problems from codeforces.
 » 7 months ago, # |   +5 Nice initiative. I liked ADE2.
 » 7 months ago, # | ← Rev. 2 →   +3 ADE (3) practice mashup will start on 12 July 2022 at 5:35 UTC.number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000UPD: registration is open;PS: my intern drive is ongoing, so i wasn't preparing mashups for few days.
 » 6 months ago, # | ← Rev. 2 →   0 ADE (4) practice mashup will start on 19 July 2022 at 5:35 UTC.number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000UPD: registration is open;
 » 6 months ago, # | ← Rev. 2 →   0 ADE (5) practice mashup will start on 30 July 2022 at 09:35 UTC.number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000 registration is open;
 » 6 months ago, # |   0 ADE (6) practice mashup will start on 31st July 2022 at 05:35 UTC (11:05 IST).number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000registration is open;
 » 6 months ago, # |   0 ADE (7) practice mashup will start on 1st August 2022 at 05:35 UTC (11:05 IST).number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000registration is open;
 » 6 months ago, # |   0 ADE (8) practice mashup will start on 2nd August 2022 at 05:35 UTC (11:05 IST).number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000registration is open;
 » 6 months ago, # | ← Rev. 2 →   +8 ADE (9) practice mashup will start on 3rd August 2022 at 10:05 UTC (15:35 IST).number of problems: 3duration of mashup: 2:30 hrsratings of problems: 800, 1900, 2000registration is open;
 » 6 months ago, # |   +8 ADE (10) Practice Mashup will start on 5th August 2022 at 10:05 UTC (15:35 IST).Problems count: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 6 months ago, # |   +8 ADE (11) Practice Mashup will start on 9th August 2022 at 09:35 UTC (15:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 6 months ago, # | ← Rev. 2 →   +8 ADE (12) Practice Mashup will start on 10th August 2022 at 10:05 UTC (15:35 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 6 months ago, # |   0 AD2E (1) Practice Mashup will start on 13th August 2022 at 05:35 UTC (11:05 IST).Count of problems: 4Duration: 3:00 hrsRatings of problems: 800, 1900, 1900, 2000
 » 5 months ago, # | ← Rev. 2 →   0 AD2E (2) Practice Mashup will start on 17th August 2022 at 06:35 UTC (12:05 IST).Count of problems: 4Duration: 3:00 hrsRatings of problems: 800, 1900, 1900, 2000
 » 5 months ago, # |   0 AD2E (3) Practice Mashup will start on 19th August 2022 at 07:35 UTC (13:05 IST).Count of problems: 4Duration: 4:00 hrsRatings of problems: 800, 1900, 1900, 2000
 » 2 months ago, # |   0 Today's practice mashup will start at 05:35 UTC (11:05 IST).Count of problems: 3 Duration: 2:30 hrs Ratings of problems: 800, 1900, 2000
 » 2 months ago, # |   0 Today's practice mashup will start at 05:35 UTC (11:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   0 Today's (20th Nov 22) practice mashup will start at 09:05 UTC (14:35 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   0 Today's (24th Nov 22) practice mashup will start at 05:35 UTC (11:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   0 cool
 » 2 months ago, # |   0 Today's (25th Nov 22) practice mashup will start at 05:45 UTC (11:15 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # | ← Rev. 2 →   0 Today's (27th Nov 22) practice mashup will start at 06:35 UTC (12:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   +3 Today's (28th Nov 22) practice mashup will start at 05:35 UTC (11:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   0 Today's (29th Nov 22) practice mashup will start at 05:35 UTC (11:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   0 Today's (1st Dec 22) practice mashup will start at 05:35 UTC (11:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   +1 Today's (3rd Dec 22) practice mashup will start at 06:35 UTC (12:05 IST).Count of problems: 3Duration: 2:00 hrsRatings of problems: 800, 1900, 2000
 » 2 months ago, # |   0 Today's (4th Dec 22) practice mashup will start at 06:35 UTC (12:05 IST).Count of problems: 3Duration: 2:00 hrsRatings of problems: 800, 1900, 2000
 » 7 weeks ago, # |   0 Today's (11th Dec 22) practice mashup will start at 05:35 UTC (11:05 IST).Count of problems: 3Duration: 2:30 hrsRatings of problems: 800, 1900, 2000
 » 7 weeks ago, # |   +27 Glad to inform you guys, that I have finally became a master. Now, I don't know what to do next, maybe I could come up with a new blog "Mashups for aspiring IMs" ? Lol.Do anyone of you have any other interesting ideas for me or the community ?
 » 7 weeks ago, # |   0 can someone explain problem c of 11th Dec that why is the probability of a student who reads message mi is ki/t if t>ki ? shouldn't it be ncr(t,ki-1)/ncr(t,ki) where we are fixing the message which the ith student to read. In question it was given all k sets are equiprobable but I couldn't understand why it is the reason for probability as ki/t ? 
•  » » 5 weeks ago, # ^ |   +8 Sorry for late reply, but it's good you asked this. Actually, when you're fixing the message $m_i$, then you have to choose rest $k_i - 1$ messages out of $t - 1$ messages (note that total messages would also decrease by 1). So, the numerator in your formula was wrong.
•  » » » 5 weeks ago, # ^ |   +8 Thanks for bringing me to peace with this question. Guess newbie things.. I mess up with indexing stuff
•  » » » 5 weeks ago, # ^ | ← Rev. 3 →   +8 Thanks great mashups for beg
 » 5 weeks ago, # |   0 is it recommendable for greys?
•  » » 4 weeks ago, # ^ |   0 greys can try to solve solve 1200-2000 problems. (+500) of your rating is recommended range to maintain balance between upsolving and not getting demotivated