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The Code Century
One hundred foundational problems. Solve them anywhere you like, tick them here, earn the Code Centurion certificate.
01Numbers & Warm-ups
Friendly number puzzles that build your loop, remainder and digit-handling instincts.
10 problems
02Strings I
Strings are the most asked fresher topic. Learn to walk a string with confidence.
10 problems
03Arrays I
One pass and a few variables. These are the core moves behind most array questions.
10 problems
04Searching & Sorting
How computers find and order data. The backbone of every coding round.
10 problems
05Patterns & Loops
Nested loops become second nature once you can draw any pattern on demand.
10 problems
06Math & Logic
Sharpen the math sense that turns scary-sounding questions into simple ones.
10 problems
07Strings II
Move from single characters to real parsing with stacks, prefixes and ciphers.
10 problems
08Matrices
Think in rows and columns and keep your indices honest.
10 problems
09Recursion
See the smaller problem inside the big one. Recursion rewards clear thinking.
10 problems
10Interview Classics
The questions interviewers ask again and again. Finish strong.
10 problems
The Code Centurion certificate
Finish all one hundred problems, sign the honor code, and we issue a named, verifiable certificate you can share anywhere.