C++ Programming Code Examples
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Matching Elements Using the equals and mismatch Operations
/* Matching Elements Using the equals and mismatch Operations */
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
template<class Container, class Iterator>
void ShowElement(Container& c, Iterator& itor);
int main()
{
typedef vector<int>::iterator VectorInterator;
vector<int> intValueVector(4);
intValueVector[0] = 1;
intValueVector[1] = 2;
intValueVector[2] = 3;
intValueVector[3] = 4;
vector<int> intValueVector2(3);
intValueVector2[0] = 1;
intValueVector2[1] = 2;
intValueVector2[2] = 3;
VectorInterator first1 = intValueVector.begin();
VectorInterator last1 = intValueVector.end();
VectorInterator first2 = intValueVector2.begin();
if (equal(first1, last1, first2))
cout << "intValueVector == intValueVector2\n";
else
cout << "intValueVector != intValueVector2\n";
pair<VectorInterator, VectorInterator> pi = mismatch(first1, last1, first2);
cout << "First mismatch element in intValueVector = ";
ShowElement(intValueVector, pi.first);
cout << "\n";
cout << "First mismatch element in intValueVector2 = ";
ShowElement(intValueVector2, pi.second);
cout << "\n";
return 0;
}
template<class Container, class Iterator>
void ShowElement(Container& c, Iterator& itor)
{
if (itor != c.end())
{
if (itor != c.begin())
cout << *itor << "\tthe previous element is " << *(itor - 1);
else
cout << "first";
}
else
cout << "last";
}
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Return first position where two ranges differ. Compares the elements in the range [first1,last1) with those in the range beginning at first2, and returns the first element of both sequences that does not match. C++ Algorithm mismatch() function compares both the containers to spot for any mismatch of values. The function returns the first element of both the containers that does not match. The elements are compared using operator== (or pred, in version (2)). The function shall not modify any of its arguments. This can either be a function pointer or a function object. Function returns a pair, where its members first and second point to the first element in both sequences that did not compare equal to each other.
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