STL常用算法: fill,rotate,rotate_copy.

fill算法用来填充容器，当然创建容器的时候，也可以达到与fill算法一样的效果.

#include <iostream>#include <vector>#include <algorithm>using namespace std;//fill算法的手动实现.template <typename T, typename V>void myFill(T first, T last, const V value){    while (first != last)    {        *first++ = value;    }}int main(){    vector<int> s = {1,2,3,4,5,6,7};    //用来让指定范围内的元素填充为5.    fill(s.begin(), s.begin() + 3, 5);  // 5 5 5 4 5 6 7    //当然这样也是可以的.给容器temp填充了10个5.    vector<int> temp(10,5);    system("pause");    return 0;}

rotate用来循环容器内的元素.但它和swap_ranges不同，它旋转的元素个数不用相等.

#include <iostream>#include <vector>#include <algorithm>using namespace std;//rotate的实现.template <typename T>void myRotate(T first, T mid, T last){    //这个实现挺有趣的,倒序即可实现.    reverse(first, mid);    reverse(mid, last);    reverse(first, last);}int main(){    vector<int> s = {1,2,3,4,5,6,7};    rotate(s.begin(), s.begin() + 3, s.end());  // 4 5 6 7 1 2 3    system("pause");    return 0;}

既然有rotate,那么肯定有rotate_copy了.

template <typename T>void myRotate_copy(T first, T mid, T last, T new_first){    //一般有copy的算法，都比较简单实现.    T temp = mid;    while (temp != last)    {        *new_first = *temp++;    }    while (first != mid)    {        *new_first = *first++;    }}