# Suggested problems

## find the number of all notokolides

March 29, 2017, 8:39 a.m. by mahdihasanipoor3

## A Rapid Introduction to Molecular Biology

Figure 1. A 1900 drawing of onion cells at different stages of mitosis by Edmund Wilson.

Making up all living material, the cell is considered the building block of life. The nucleus, a component of most eukaryotic (nonbacterial) cells, has been known to be the hub of cellular activity for 150 years. Seen under a light microscope, the nucleus appears to simply be a darker region of the cell, but as we increase magnification, we find a hodgepodge of substances in the nucleus, which undergoes a flurry of activity leading up to and during mitosis, or cell division; see Figure 1.

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## Problem

A string is simply an ordered collection of symbols selected from some alphabet and formed into a word; the length of a string is the number of symbols that it contains.

An example of an DNA string (whose alphabet contains the symbols A, C, G, and T) is ATGCTTCAGAAAGGTCTTACG.

Given: A DNA string $s$ of length at most 1000 nucleotides.

Return: Four integers corresponding to the number of times that the symbols A, C, G, and T occur in $s$.

## Sample Dataset

AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC

20 12 17 21