STL：算法_C/C++/C#

STL：算法

参考文献《大道至简：C++STL》

for_each()、count()、min_element()/max_element()

#include 
#include 
#include 
#include 
#include 

#ifndef __print__
    #define __print__(x) {std::cout << x << " ";}
#endif

#ifndef newline
    #define newline() {std::cout << std::endl;}
#endif

using namespace std;

template  void _pow(T& t) {t *= t;}

template  void print(const T& t){__print__(t);}

class SUM
{
private:
    long total;
public:
    SUM():total(0){}
    void operator()(int val)
    {
        total += val;
    }
    operator double()
    {
        return static_cast(total);
    }
};

bool is_even(const int& x){return x % 2 == 0;}
template  bool abs_val(const T& t1, const T& t2){return abs(t1) < abs(t2);};

int main()
{



    vector vint = {1, 3, 5, 7};
    for_each(vint.begin(), vint.end(), print);
    newline();
    for_each(vint.begin(), vint.end(), _pow);
    for_each(vint.begin(), vint.end(), print);
    newline();
    double sum = for_each(vint.begin(), vint.end(), SUM());
    print(sum);
    newline();



    deque dint = {2, 5, 4, 1, 8, 3, 6};
    for_each(dint.begin(), dint.end(), print);
    newline();
    print(count(dint.begin(), dint.end(), 4));
    print(count_if(dint.begin(), dint.end(), bind2nd(greater(), 3)));
    print(count_if(dint.begin(), dint.end(), is_even));
    newline();



    list lint = {-1, 4, 6, -12, 9};
    print(*min_element(lint.begin(), lint.end()));
    newline();
    print(*max_element(lint.begin(), lint.end()));
    newline();
    print(*min_element(lint.begin(), lint.end(), abs_val));    //-1
    newline();
    print(*max_element(lint.begin(), lint.end(), abs_val));    //-12
    newline();

    return 0;
}

find()、find_if()

#include 
#include 
#include 
#include 

using namespace std;

#ifndef newline
    #define newline() {cout << endl;}
#endif

template  void print(const T& t){cout << t << " ";}

template  class greater_even : public binary_function{
public:
    bool operator()(const T& key, const T& val) const{
        return key > val && key % 2 == 0;
    }
};

int main(){



    vector vec = {2, 3, 5, 7, 7, 2, 5, 6};
    for_each(vec.begin(), vec.end(), print);
    newline();

    vector::iterator vpos;
    
    vpos = find(vec.begin(), vec.end(), 5);
    print(distance(vec.begin(), vpos));
    newline();

    vpos = find_if(vec.begin(), vec.end(), bind2nd(greater_even(), 5));
    print(distance(vec.begin(), vpos));
    newline();

    return 0;
}

搜索算法

#include 
#include 
#include 
#include 
#include 

using namespace std;

#ifndef newline
    #define newline() {cout << endl;}
#endif

template  void print(const T& t){cout << t << " ";}

void search_resault(
    const vector::iterator& pos, const vector::iterator& beg, 
    const vector::iterator& end, const string& out){        
    print(out);
    if(pos == end){
        print("Not Found！");
    }
    else{
        print(distance(beg, pos));
    }
    newline();    
}

void search_resault(
    const vector::reverse_iterator& pos, const vector::iterator& beg, 
    const vector::iterator& end, const string& out){        
    print(out);
    if(pos.base() == end){
        print("Not Found！");
    }
    else{
        print(distance(beg, pos.base()));
    }
    newline();    
}

bool check_even(const int& elem, const bool& is_even){
    return is_even ? elem % 2 == 0 : elem % 2 != 0;
}

bool diff4th(const int& a, const int& b){
    return b == a - 4;
}

int main(){



    vector vec = {1, 2, 3, 4, 5, 6, 2, 3, 4, 7, 7, 8};

    for_each(vec.begin(), vec.end(), print);
    newline();

    vector::iterator vpos;

    vpos = search_n(vec.begin(), vec.end(), 3, 4);
    search_resault(vpos, vec.begin(), vec.end(), "vec中3个连续为4的值的起始位置为");

    vpos = search_n(vec.begin(), vec.end(), 3, 3, greater());
    search_resault(vpos, vec.begin(), vec.end(), "vec中3个连续大于3的值的起始位置为");

    vector subvec = {2, 3, 4};
    vpos = search(vec.begin(), vec.end(), subvec.begin(), subvec.end());
    search_resault(vpos, vec.begin(), vec.end(), "subvec在vec中的起始位置为");

    vector is_even = {true, false, true};
    vpos = search(vec.begin(), vec.end(), is_even.begin(), is_even.end(), check_even);
    search_resault(vpos, vec.begin(), vec.end(), "vec中连续三个匹配is_even的起始位置为");

    vpos = find_end(vec.begin(), vec.end(), is_even.begin(), is_even.end(), check_even);
    search_resault(vpos, vec.begin(), vec.end(), "vec中连续三个匹配is_even的最后一组的起始位置为");

    vpos = find_first_of(vec.begin(), vec.end(), subvec.begin(), subvec.end());
    search_resault(vpos, vec.begin(), vec.end(), "vec中连续三个匹配subvec的第一个字串的起始位置为");

    vector::reverse_iterator rvpos;

    rvpos = find_first_of(vec.rbegin(), vec.rend(), subvec.begin(), subvec.end());
    search_resault(rvpos, vec.begin(), vec.end(), "vec中逆向连续三个匹配subvec的第一个字串的起始位置为");

    vpos = adjacent_find(vec.begin(), vec.end());
    search_resault(vpos, vec.begin(), vec.end(), "vec中连续两个相等元素的起始位置为");

    vpos = adjacent_find(vec.begin(), vec.end(), diff4th);
    search_resault(vpos, vec.begin(), vec.end(), "vec中后一个元素比前一个元素小4的起始位置为");

    return 0;
}

比较算法

#include 
#include 
#include 

using namespace std;

#ifndef newline
    #define newline() {cout << endl;}
#endif

template  void print(const T& t){
    cout << t << " ";
}

template  void print(const T& t1, const T& t2){
    cout << t1 << "," << t2;
}

bool relation(const int& x, const int& y){
    return x == y - 1;
}

int main(){



    vector va = {2, 3, 4, 5, 6, 9};
    vector vb = {3, 4, 5, 6, 7, 8};

    print(equal(va.begin(), va.end(), vb.begin()));     //0
    newline();

    print(equal(va.begin(), va.end(), vb.begin(), relation));       //0
    newline();

    pair::iterator, vector::iterator> pos;

    pos = mismatch(va.begin() + 1, va.end(), vb.begin());
    print(*pos.first, *pos.second);     //9,7
    newline();

    pos = mismatch(va.begin(), va.end(), vb.begin(), less_equal());
    print(*pos.first, *pos.second);     //9,8
    newline();

    print(lexicographical_compare(va.begin(), va.end(), vb.begin(), vb.end()));     //1
    newline();

    return 0;
}

修改性算法

#include 
#include 
#include 
#include 

using namespace std;

#ifndef newline
    #define newline() {cout << endl;}
#endif

template  void print(const T& t){
    cout << t << " ";
}

template  void print_list(const list& t){
    for_each(t.begin(), t.end(), print);
    newline();
}

template  void print_vector(const vector& t){
    for_each(t.begin(), t.end(), print);
    newline();
}

class custom{
public:
    custom(const int& _times):times(_times){}
    int operator()(const int& elem1, const int& elem2){
        return (elem1 + elem2) * times;
    }
private:
    int times;
};

int main(){

    vector va = {1, 2, 3, 4, 5, 6, 7};
    list la;



    copy(va.begin(), va.end(), back_inserter(la));
    print_list(la);     //1 2 3 4 5 6 7

    copy_backward(va.begin() + 2, va.begin() + 5, la.end());
    print_list(la);     //1 2 3 4 3 4 5
    la.clear();



    transform(va.begin(), va.end(), back_inserter(la), negate());
    print_list(la);     //-1 -2 -3 -4 -5 -6 -7

    transform(va.begin(), va.end(), la.begin(), bind2nd(multiplies(), 10));
    print_list(la);     //10 20 30 40 50 60 70

    transform(va.begin(), va.end(), la.begin(), la.begin(), multiplies());
    print_list(la);     //10 40 90 160 250 360 490
    la.clear();
    
    transform(va.begin(), va.end(), la.begin(), back_inserter(la), plus());
    print_list(la);     //1 3 6 10 15 21 28
    la.clear();

    transform(va.begin(), va.end(), la.begin(), back_inserter(la), custom(2));
    print_list(la);     //2 8 22 52 114 240 494 



    vector vb = {2, 8, 22, 52, 114, 240, 494};

    swap(va, vb);
    print_vector(va);   //2 8 22 52 114 240 494
    print_vector(vb);   //1 2 3 4 5 6 7

    swap_ranges(va.begin() + 2, va.begin() + 5, vb.begin());;
    print_vector(va);   //2 8 1 2 3 240 494
    print_vector(vb);   //22 52 114 4 5 6 7 



    fill(vb.begin(), vb.begin() + 3, 0);
    print_vector(vb);   //0 0 0 4 5 6 7

    fill_n(vb.begin(), 3, 1);
    print_vector(vb);   //1 1 1 4 5 6 7

    generate(vb.begin(), vb.begin() + 3, rand);
    print_vector(vb);   //41 18467 6334 4 5 6 7 

    generate_n(vb.begin(), 3, rand);
    print_vector(vb);   //26500 19169 15724 4 5 6 7



    replace(vb.begin(), vb.end(), 4, 99);
    print_vector(vb);   //26500 19169 15724 99 5 6 7

    replace_if(vb.begin(), vb.end(), bind2nd(greater(), 100), -1);
    print_vector(vb);   //-1 -1 -1 99 5 6 7



    list lb;
    print_list(la);     //2 8 22 52 114 240 494
    
    reverse(la.begin(), la.end());
    print_list(la);     //494 240 114 52 22 8 2

    list::iterator posb = la.begin(), pose = la.end();
    advance(posb, 1);
    advance(pose, -1);
    reverse(posb, pose);
    print_list(la);     //494 8 22 52 114 240 2

    reverse_copy(la.begin(), la.end(), back_inserter(lb));
    print_list(lb);     //2 240 114 52 22 8 494



    print_vector(va);   //2 8 1 2 3 240 494
    print_vector(vb);   //-1 -1 -1 99 5 6 7

    rotate(va.begin(), va.begin() + 3, va.end());
    print_vector(va);   //2 3 240 494 2 8 1

    rotate_copy(va.begin(), va.begin() + 3, va.end(), vb.begin());
    print_vector(va);   //2 3 240 494 2 8 1
    print_vector(vb);   //494 2 8 1 2 3 240 

    return 0;
}

STL：算法

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