在C ++中替换两个迭代器之间的范围 [英] Replacing a range between two iterators in C++

问题描述

假设我有两个非常数迭代器开始和结束.我想用其他两个迭代器之间的值完全替换begin和end之间的范围.我知道使用非常量迭代器，我可以使用以下语法.

Assume I have two non-constant iterators begin and end. I want to completely replace the range between begin and end with values, that are between two other iterators. I know with non-constant iterators I can use the following syntax.

*begin = *result.begin();
*end = *result.end();

但这只会更改开始和结束迭代器后面的值

But this will only change the values behind begin and end iterators

更准确地说.我有一个初始向量

To be more precise. I have an initial vector

          {1, 2, 3, 4, 5, 6, 7}
           ^           ^
         begin        end 

和其他称为result的向量，其中包含

and some other vector called result, which contains

       {6, 6, 3, 5, 4, 13, 99}
           ^           ^
         begin        end 

最后，我希望我的初始数组看起来像

at the end I want my initial array to look like

       {6, 3, 5, 4, 5, 6, 7}

推荐答案

使用 <代码> std :: copy() ，可以这样做:

Using std::copy(), it can be done like this:

#include <iostream>
#include <vector>
#include <algorithm>

void printVector(const std::vector<int>& v) {
    bool first = true;
    std::cout << '{';
    for (int i : v) {
        if (!first) std::cout << ", ";
        std::cout << i;
        first = false;
    }
    std::cout << "}\n";
}

int main(void) {
    std::vector<int> v1 = {1, 2, 3, 4, 5, 6, 7};
    std::vector<int> v2 = {6, 6, 3, 5, 4, 13, 99};

    printVector(v1);
    printVector(v2);

    std::vector<int>::iterator dest_begin = v1.begin();
    std::vector<int>::iterator src_begin = std::next(v2.begin(), 1);
    std::vector<int>::iterator src_end = std::next(v2.begin(), 5);

    std::copy(src_begin, src_end, dest_begin);

    printVector(v1);

    return 0;
}

输出:

{1, 2, 3, 4, 5, 6, 7}
{6, 6, 3, 5, 4, 13, 99}
{6, 3, 5, 4, 5, 6, 7}

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