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This article mainly explains "how C++ cuts String objects". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn how C++ cuts String objects.

Kernel function

The function implemented by the code is to call the find function and the substr function in the String library.

Find function size_type find (const basic_string & str,size_type pos=0)

The find function does the simplest search, looking for the string (str) specified by the parameter, and if it finds a value that returns a String::size_type, it represents the subscript where the match occurs. If it is not found, a static member named string::npos is returned. The C++ standard library defines npos as a const string:: size_type type and initializes it with a value of-1. Because npos is a unsigned type, this initial value means that npos is equal to the maximum possible size of any string.

Parameter str,pos indicates that the search for str starts from the pos location

In addition to find operations, string supports the following operations

Str.find (args) finds the location of the first occurrence of args in str

Str.rfind (args) finds the location where args last appeared in str

Str.find_first_of (args) finds the location where the first character in args appears for the first time in str

Str.find_last_of (args) finds the location of the last occurrence of the first character in args in str

Str.find_first_not_of (args) finds the first character in args in str that is not in atgs

Str.find_last_not_of (args) finds the last character in args in str that is not in atgs

Substr function string substr (size_type pos=0,size_type count=npos)

The main function of substr is to copy strings, which requires you to start at the specified location pos and have a specified length count. If no length or pos+count > source string length is specified, the substring will continue to the end of the source string

Numerical conversion

Since we need to convert string types to int types in this sample, we will briefly introduce the following common numerical conversions for string

Convert int to string

Int iTunes 42 * * string s=to_string (I)

Convert string to int

String str='42';stoi (str); input sample nums = [3meme 2jue 4], target = 6 output style

3 2 4

six

Code implementation

# include#include#includeusing namespace std;void spiltStr (string str,const string & split,vector&strlist) {strlist.clear (); if (str== "") return; string strs=str+split; size_t pos=strs.find (split); int steps=split.size (); while (poster strings. Npos) {/ / substr copy string, starting position, number of copied characters string temp=strs.substr (0pencepos) Strlist.push_back (temp); strs=strs.substr (pos+steps,strs.size ()); pos=strs.find (split);}} int main () {vectornum; vectorstrlist; string inputStr; string tempStr; int target; getline (cin,inputStr); if (inputStr== ") {return 0;} / / split the input string spiltStr (inputStr," [", strlist) SpiltStr (strlist [1], "]", strlist); spiltStr (strlist [0], ",", strlist); / / write the value of vectorspiltStr to vectornums for (auto i:strlist) {num.push_back (stoi (I));} spiltStr (inputStr, "=", strlist); / / spiltStr (strlist.back (), "=", strlist); target=stoi (strlist.back ()) For (auto i:num) {cout

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