c/c++中vector 去重，交集，并集，查找，求最大最小值等操作

最新推荐文章于 2025-02-06 18:46:55 发布

lch_vision

最新推荐文章于 2025-02-06 18:46:55 发布

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分类专栏： c++ 文章标签： vector 去重删除交集并集最大最小值

本文链接：https://blog.youkuaiyun.com/lch_vison/article/details/91490275

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元素删除可参考 http://c.biancheng.net/view/429.html

去重可参考https://blog.youkuaiyun.com/HE19930303/article/details/50579996

对vector中的pair排序 https://www.cnblogs.com/bigyang/p/8590552.html

批量赋值：https://blog.youkuaiyun.com/t46414704152abc/article/details/79229715

以下代码参考https://www.cnblogs.com/mayouyou/p/8921598.html

#include <iostream>
#include <vector>
#include <algorithm> //sort函数、交并补函数
#include <iterator> //求交并补使用到的迭代器
using namespace std;

//打印容器vector
void print_vector(vector<int> v)
{
    if(v.size()>0){
        cout<<"{";  
        for(int i=0;i<int(v.size());i++){  
            cout<<v[i]<<",";  
        }  
        cout<<"\b}";  
    }
    else{
        cout<<"{}";
    }
}

//容器vector中元素的去重
vector<int> unique_element_in_vector(vector<int> v)
{
    vector<int>::iterator vector_iterator;
    sort(v.begin(),v.end());
    vector_iterator = unique(v.begin(),v.end());
    if(vector_iterator != v.end()){
        v.erase(vector_iterator,v.end());
    }
    return v;
}

//两个vector求交集
vector<int> vectors_intersection(vector<int> v1,vector<int> v2)
{
    vector<int> v;
    sort(v1.begin(),v1.end());   
    sort(v2.begin(),v2.end());   
    set_intersection(v1.begin(),v1.end(),v2.begin(),v2.end(),back_inserter(v));//求交集 
    return v;
}

//两个vector求并集
vector<int> vectors_set_union(vector<int> v1,vector<int> v2)
{
    vector<int> v;
    sort(v1.begin(),v1.end());   
    sort(v2.begin(),v2.end());   
    set_union(v1.begin(),v1.end(),v2.begin(),v2.end(),back_inserter(v));//求交集 
    return v;
}

//判断vector的某一元素是否存在
bool is_element_in_vector(vector<int> v,int element)
{
    vector<int>::iterator it;
    it=find(v.begin(),v.end(),element);
    if (it!=v.end()){
        return true;
    }
    else{
        return false;
    }
}

int main(){
    vector<int> v1,v2,v;
    v1.push_back(22);v1.push_back(22);v1.push_back(23);v2.push_back(23);v2.push_back(24);
    cout<<"v1是否存在1这个元素？"<<is_element_in_vector(v1,1)<<endl;
    cout<<"对v1去重：";
    v1=unique_element_in_vector(v1);
    print_vector(v1);
    cout<<endl;
    cout<<"求v1与v2的交集：";
    v=vectors_intersection(v1,v2);
    print_vector(v);
    cout<<endl;
    cout<<"求v1与v2的并集：";
    v=vectors_set_union(v1,v2);
    print_vector(v);
    
    //求最大最小值
    vector<double>::iterator biggest = std::max_element(v.begin(), v.end());
    cout << "Max element is " << *biggest<< " at position " << distance(v.begin(), biggest) << endl;
    vector<double>::iterator smallest= std::min_element(v.begin(), v.end());
    cout << "Min element is " << *smallest<< " at position " << distance(v.begin(), smallest) << endl;


    return 0;
}