September 2019
Intermediate to advanced
816 pages
18h 47m
English
Content preview from Java Coding Problems
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17. Counting substring occurrences in a string
Counting the number of occurrences of a string in another string is a problem that can have at least two interpretations:
- 11 in 111 occurs 1 time
- 11 in 111 occurs 2 times
In the first case (11 in 111 occurs 1 time), the solution can rely on the String.indexOf() method. One of the flavors of this method allows us to obtain the index within this string of the first occurrence of the specified substring, starting at the specified index (or -1, if there is no such occurrence). Based on this method, the solution can simply traverse the given string and count the given substring occurrences. The traversal starts from position 0 and continues until the substring is not found:
public static int countStringInString(String ...