字符串的构造

Question

You are given three positive integers n, a and b. You have to construct a string s of length n consisting of lowercase Latin letters such that each substring of length a has exactly b distinct letters.

Please provide hints on how to solve. Please dont solve the question. Should I use arrays?

Answer 1

No. This is an easy problem, not necessary to use any external memory like-array or others.

You need just to iterate the loop and generate the characters so that you can construct a string following given conditions. As you are generating characters, you can use ASCII values per iteration with loop to print the characters sequentially (not randomly, otherwise you may confuse).

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Again no need to think about the occurrence of exact b numbers of characters in each substrings as you are only generating the b number of characters each time.

Hopeful to your understanding

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example : (in C++)

for(int i = 0;  i < n; ++i)
 cout<<char('a'+i%b);