Change or delete elements of vector - c++

Question

I have following problem. My vector contains pairs of pairs (see example below).
In the example below I will push_back vector with some "random" data.
What will be best solution to delete the vector element if any of their values will be equal i.e. 100 and update value if less than 100.
i.e.
typedef std::pair<int, int> MyMap;
typedef std::pair<MyMap, MyMap> MyPair;
MyMap pair1;
MyMap pair2;
In first example I want to update this pair because pair1.first is less than 100
pair1.first = 0;
pair1.second = 101;
pair2.first = 101;
pair2.second = 101;
In second example I want to delete this pair because pair2.first is equal to 100
pair1.first = 0;
pair1.second = 101;
pair2.first = 100;
pair2.second = 101;
Using functor "check" I am able to delete one or more elements (in this example just one).
It is possible to increase every value of that pair by 1 using std::replace_if function?
Is there any function that will update this value if any of these values will be lower then "X" and delete if any of these values will be equal "X"?
I know how to do it writing my own function but I am curious.
#include "stdafx.h"
#include<algorithm>
#include<vector>
#include<iostream>
typedef std::pair<int, int> MyMap;
typedef std::pair<MyMap, MyMap> MyPair;
void PrintAll(std::vector<MyPair> & v);
void FillVectorWithSomeStuff(std::vector<MyPair> & v, int size);
class check
{
public:
check(int c)
: cmpValue(c)
{
}
bool operator()(const MyPair & mp) const
{
return (mp.first.first == cmpValue);
}
private:
int cmpValue;
};
int _tmain(int argc, _TCHAR* argv[])
{
const int size = 10;
std::vector<MyPair> vecotorOfMaps;
FillVectorWithSomeStuff(vecotorOfMaps, size);
PrintAll(vecotorOfMaps);
std::vector<MyPair>::iterator it = std::find_if(vecotorOfMaps.begin(), vecotorOfMaps.end(), check(0));
if (it != vecotorOfMaps.end()) vecotorOfMaps.erase(it);
PrintAll(vecotorOfMaps);
system("pause");
return 0;
}
std::ostream & operator<<(std::ostream & stream, const MyPair & mp)
{
stream << "First:First = " << mp.first.first << " First.Second = " << mp.first.second << std::endl;
stream << "Second:First = " << mp.second.first << " Second.Second = " << mp.second.second << std::endl;
stream << std::endl;
return stream;
}
void PrintAll(std::vector<MyPair> & v)
{
for (std::vector<MyPair>::iterator it = v.begin(); it != v.end(); ++it)
{
std::cout << *it;
}
}
void FillVectorWithSomeStuff(std::vector<MyPair> & v, int size)
{
for (int i = 0; i < size; ++i)
{
MyMap m1(i + i * 10, i + i * 20);
MyMap m2(i + i * 30, i + i * 40);
MyPair mp(m1, m2);
v.push_back(mp);
}
}

Answer 1

Use std::stable_partition, along with std::for_each:
#include <algorithm>
//...partition the elements in the vector
std::vector<MyPair>::iterator it =
std::stable_partition(vecotorOfMaps.begin(), vecotorOfMaps.end(), check(0));
//erase the ones equal to "check"
vecotorOfMaps.erase(vecotorOfMaps.begin(), it);
// adjust the ones that were left over
for_each(vecotorOfMaps.begin(), vecotorOfMaps.end(), add(1));
Basically, the stable_partition places all the items you will delete in the front of the array (the left side of the partiton it), and all of the other items to the right of it.
Then all that is done is to erase the items on the left of it (since they're equal to 100), and once that's done, go through the resulting vector, adding 1 to eac