grep+ found these files to match your search:
p412.cpp: //easy, trivial, gcd, number theory, brute force p10365.cpp: //easy, trivial, math, number theory, factoring, mod, divisibility, good p408.cpp: //easy, trivial, number theory, short, 4 lines, gcd p10141.cpp: //easy, trivial, io, getline, good, excellent, useless input p11559.cpp: //easy, trivial, brute force p10370.cpp: //easy, trivial, short, math, statistics, stats, mean, median, good, excellent p10452.cpp: //easy, trivial, simulation, following instructions p10300.cpp: //easy, trivial, short p913.cpp: //easy, trivial, math, short p10055.cpp: //easy, trivial, math, ridiculously easy, gotcha, good, careful reading p11548.cpp: //easy, trivial, brute force p11332.cpp: //easy, trivial p11292.cpp: //easy, trivial, greedy p498.cpp: //easy, trivial, horner, polynomial evaluation p11556.cpp: //easy, trivial, short p216.cpp: //easy, trivial, brute force, hamiltonian path p638.cpp: //easy, trivial, brute force p11360.cpp: //easy, trivial, simulation p10550.cpp: //easy, trivial, combination lock p499.cpp: //easy, trivial, map, character frequencies p11172.cpp: //easy, trivial p10865.cpp: //easy, trivial, short, brute force p278.cpp: //easy, trivial, chess, math p737.cpp: //easy, trivial, geometry, min, max, cube intersection, cute p11777.cpp: //easy, trivial, simulation, careful coding p488.cpp: //easy, trivial, output p697.cpp: //easy, trivial, io, printf, stupid, annoying, I hate these, short p10082.cpp: //easy, trivial, input, io, map, wertyu, good p474.cpp: //easy, trivial, math, printf, io p10849.cpp: //easy, trivial, chess, bishop moves p11313.cpp: //easy, trivial, math p454.cpp: //multiple input, easy, trivial, anagrams, sorting p576.cpp: //easy, trivial, io, haiku, haiku review, good, excellent, short, good code, scanf p12764.cpp: //easy, trivial, output p10035.cpp: //easy, trivial, math, number theory, misc, number of carries in addition, good, short p712.cpp: //easy, trivial, io, trees, good, short p445.cpp: //easy, trivial p11044.cpp: //easy, trivial, math, short p621.cpp: //easy, trivial, stupid, bad, poorly defined p11498.cpp: //easy, trivial p490.cpp: //easy, trivial, io, getline p11364.cpp: //easy, trivial p10260.cpp: //easy, trivial, soundex p11078.cpp: //easy, trivial p10420.cpp: //easy, trivial, getline, io p10008.cpp: //easy, trivial, datastructures, map, cryptanalysis, good, excellent, short p10646.cpp: //easy, trivial, simulation, cards p10879.cpp: //easy, trivial, math, factoring p11677.cpp: //easy, trivial, short p11132.cpp: //easy, trivial, bad, horrible p11530.cpp: //easy, trivial, simulation p11614.cpp: //easy, trivial, math p11152.cpp: //easy, trivial, math, geometry p10215.cpp: //easy, trivial, math, geometry, calculus, short, tiny, rounding, bad p10282.cpp: //easy, trivial, map, input, io, getline, short, tiny p11608.cpp: //easy, trivial, simulation p11369.cpp: //easy, trivial, greedy, sorting p486.cpp: //easy, trivial, tedious, natural language numbers p11059.cpp: //easy, trivial, brute force p482.cpp: //multiple input, easy, trivial p10489.cpp: //easy, trivial, short, math, number theory, modular arithmetic p10815.cpp: //easy, trivial, set, strings p11588.cpp: //easy, trivial p11547.cpp: //easy, trivial p494.cpp: //easy, trivial, parsing p11713.cpp: //easy, trivial p10346.cpp: //easy, trivial, math, number theory, integer division, mod, good, excellent p594.cpp: //easy, trivial, little endian, big endian, good, short, union, swap, example, excelent p10019.cpp: //easy, trivial, math, horner, bases, bit counting, good p11541.cpp: //easy, trivial, input p10038.cpp: //easy, trivial, datastructure, array p880.cpp: //easy, trivial, math, cantor fractions p11121.cpp: //easy, trivial, math, base conversion p10050.cpp: //easy, trivial, simulation, math, number theory, modular arithmetic, short p11520.cpp: //easy, trivial, brute force p673.cpp: //easy, trivial, parentheses, stack, grammars, parsing, gotcha, good p11063.cpp: //easy, trivial p11743.cpp: //easy, trivial p382.cpp: //easy, trivial, short, math, number theory, perfect numbers p11309.cpp: //easy, trivial, brute force p865.cpp: //easy, trivial p119.cpp: //easy, trivial, good, excellent p11326.cpp: //easy, trivial, math, geometry p10071.cpp: //easy, trivial, math, short, tiny, the shortest program ever p145.cpp: //easy, trivial, output, bad p10235.cpp: //easy, trivial, math, number theory, primes, sieve, gotcha, good p11130.cpp: //easy, trivial, math, geometry p414.cpp: // easy, trivial p332.cpp: //easy, trivial, math, input, decimal fractions, good, excellent p492.cpp: //easy, trivial, parsing, getline p11760.cpp: //easy, trivial p12765.cpp: //easy, trivial p10302.cpp: //easy, trivial, short, long long p11715.cpp: //easy, trivial, math, bad, numerical errors p10499.cpp: //easy, trivial, math, geometry, short (3 lines), good, excellent p11734.cpp: //easy, trivial, input p455.cpp: //multiple input, easy, trivial, strings, see 10298 p10683.cpp: //easy, trivial, math, good, short, tiny p10530.cpp: //easy, trivial, game, guessing game p460.cpp: //multiple input, easy, trivial, geometry in integers, short p10642.cpp: //easy, trivial, math, cantor's diagonalization p10800.cpp: //easy, trivial, io p10851.cpp: //easy, trivial, binary numbers, ascii p10340.cpp: //easy, trivial, short p10286.cpp: //easy, trivial, short, math, geometry p11727.cpp: //easy, trivial p10878.cpp: //easy, trivial, parsing, bitmasks, ascii, cypher p11550.cpp: //easy, trivial, graph theory p496.cpp: //easy, trivial, very good sets p11074.cpp: //easy, trivial p11636.cpp: //easy, trivial p11716.cpp: //easy, trivial p620.cpp: //easy, trivial, recursive, parsing, stupid, bad, poorly defined p832.cpp: //easy, trivial, careful reading p10469.cpp: //easy, trivial, short, tiny, 1 line, math, good, excellent p11723.cpp: //easy, trivial, short p661.cpp: //easy, trivial, simulation p11661.cpp: //easy, trivial, short p483.cpp: //easy, trivial, io, getline, bad p136.cpp: //easy, trivial, math, number theory, primes, precomputation, pre-computation p10783.cpp: //easy, trivial, short, good p450.cpp: //easy, trivial, io, parsing, sort p10678.cpp: //easy, trivial, geometry, short, tiny p154.cpp: //easy, trivial, input, getline p10656.cpp: //easy, trivial, short, wtf?! p458.cpp: //easy, trivial, good, encryption, easiest ever p10297.cpp: //easy, trivial, short, geometry p489.cpp: //easy, trivial, good set application, simulation p10693.cpp: //easy, trivial, math, calculus, short, tiny p10424.cpp: //easy, trivial p352.cpp: //easy, trivial, dfs, flood fill p272.cpp: //easy, trivial, parsing, short, tiny p10222.cpp: //easy, trivial, short p591.cpp: //easy, trivial, good, excellent, short
grep+ searches the database of Valladolid problems that I solved (or tried to). You can give it keywords like "dp", "graphs", "math", "brute force", etc. and it will give you a list of problem numbers that (in my opinion) match the keywords. The database contains 1408 problems.
Please ignore anything that appears after "UNSOLVED:". As you probably know, not being able to solve a problem after many attempts can be very frustrating.