[c++]对vector<T>容器求交集，并集，去重

#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<string> 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<string> unique_element_in_vector(vector<string> v) {
vector<string>::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<string> vectors_intersection(vector<string> v1, vector<string> v2) {
vector<string> 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<string> vectors_set_union(vector<string> v1, vector<string> v2) {
vector<string> 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<string> v, string element) {
vector<string>::iterator it;
it = find(v.begin(), v.end(), element);
if (it != v.end()) {
return true;
} else {
return false;
}
}int trim_z(std::string &s) {
if (s.empty()) {
return 0;
}
s.erase(0, s.find_first_not_of(" "));
s.erase(s.find_last_not_of(" ") + 1); return 1;
}string trim(string &s) {
string str;
if (!s.empty()) {
s.erase(0, s.find_first_not_of(" "));
s.erase(s.find_last_not_of(" ") + 1);
}
str = s;
return str;
}void test() {
Json::Value qr_result; //"猴子尾巴", "猴子尾巴", "松鼠尾巴"
//"松鼠尾巴", "猴子尾巴", "猴子尾巴"
vector<string> qr_text;
string s1 = "松鼠尾巴";
string s2 = "猴子尾巴";
string s3 = "猴子尾巴 ";
string text = " 7ter 09, jdhfd iere*- ddw jjdjjdj ";
// trim_z(text); s3 = trim(s3);
// cout << "text==>>" << text << endl;
cout << "s3==>>" << s3 << endl; qr_text.emplace_back(s1);
qr_text.emplace_back(s2);
qr_text.emplace_back(s3); const int s = qr_text.size();
int tempTimes = 0;
Json::Value items;
string name;
for (int j = 0; j < s; ++j) {
string item = qr_text[j];
if (item != "二维码识别失败") {
int times = count(qr_text.begin(), qr_text.end(), item);
cout << "times==>" << times << endl;
if (times > tempTimes) {
tempTimes = times;
name = item;
tempTimes++;
}
}
items.append(item);
}
//封装返回的json信息
qr_result["name"] = name;
qr_result["nname"] = items;
qr_result["score"] = items.size();
qr_result["function"] = "QRcoderecognition";
cout << "json==>>" << qr_result.toStyledString() << endl;
}int main() {
// jiaoji();
// test();
vector<string> vc1{"猴子尾巴", "猴子尾巴", "猴子耳朵", "松鼠脸"};
vector<string> vc2{"猴子尾巴", "猴子耳朵", "松鼠尾巴"};
vector<string> vec; cout << "求v1与v2的交集：";
vec = vectors_intersection(vc1, vc2);
print_vector(vec);
cout << endl;
cout << "求v1与v2的并集：";
vec = vectors_set_union(vc1, vc2);
print_vector(vec);
return 0;
}