الخوارزميات المعدِّلة: ‏transform وcopy_if وreplace

الخوارزميات المعدِّلة

std::copy

#include <algorithm>
#include <iterator>
std::vector<int> src = {1, 2, 3};
std::vector<int> dst;
std::copy(src.begin(), src.end(), std::back_inserter(dst));

std::copy_if

std::vector<int> evens;
std::copy_if(src.begin(), src.end(),
    std::back_inserter(evens),
    [](int x) { return x % 2 == 0; });

std::transform

std::vector<int> v = {1, 2, 3};
std::vector<int> sq;
std::transform(v.begin(), v.end(),
    std::back_inserter(sq),
    [](int x) { return x * x; });
// sq is {1, 4, 9}

transform بنطاقين

std::vector<int> a = {1, 2, 3};
std::vector<int> b = {10, 20, 30};
std::vector<int> sum;
std::transform(a.begin(), a.end(), b.begin(),
    std::back_inserter(sum), std::plus<int>{});
// sum is {11, 22, 33}

std::replace وstd::replace_if

std::vector<int> v = {1, 2, 3, 2};
std::replace(v.begin(), v.end(), 2, 99);
// v is {1, 99, 3, 99}

std::fill

std::vector<int> v(5);
std::fill(v.begin(), v.end(), 42);
// v is {42, 42, 42, 42, 42}

std::generate

std::vector<int> v(5);
int n = 0;
std::generate(v.begin(), v.end(), [&]() { return n++; });
// v is {0, 1, 2, 3, 4}

std::iota

#include <numeric>
std::vector<int> v(5);
std::iota(v.begin(), v.end(), 10);
// v is {10, 11, 12, 13, 14}

std::reverse

std::vector<int> v = {1, 2, 3, 4};
std::reverse(v.begin(), v.end());
// v is {4, 3, 2, 1}

std::rotate

اصطلاح المحو والإزالة باستخدام std::remove

v.erase(
    std::remove(v.begin(), v.end(), 0),
    v.end()
);

اختبار سريع

مراجعة