使用 C++ 对排序向量进行二分查找
c++server side programmingprogramming
这是一个 C++ 程序，用于在对排序向量中实现二分查找。
算法
Begin Declare a structure keycompare. Function operator()(const pair& v, const int& k) returns Booleans. Status = v.first < k. Return status. Function operator()(const pair& v, const int& k) returns Booleans. Status = k < v.first. Return status. Declare a vector v. Declare key and value pair within v of the integer datatype. Call push_back() function to insert values in v vector. Call sort() function to sort all elements of the vector v. Print “Sorted vector”. Print “Key” “Value”. for (pair& n : v) print the first and second value of n. if (binary_search(v.begin(), v.end(), 50,keycompare())) then print “50 exists in vector”. Else Print “50 does not exist”. if (binary_search(v.begin(), v.end(), 7,keycompare() )) then print “7 exists in vector”. Else Print “7 does not exist”. End.
示例代码
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
struct keycompare {
bool operator()(const pair<int, int>& v, const int& k) {
return (v.first < k);
}
bool operator()(const int& k, const pair<int, int>& v) {
return (k < v.first);
}
};
int main() {
vector<pair<int, int>> v;
v.push_back(make_pair(7, 26));
v.push_back(make_pair(6, 76));
v.push_back(make_pair(4, 16));
v.push_back(make_pair(5, 36));
sort(v.begin(), v.end());
cout<<"Sorted vector"<<endl;
cout << "KEY" << '\t' << "VALUE" << endl;
for (pair& n : v)
cout << n.first << '\t' << n.second << endl;
if (binary_search(v.begin(), v.end(), 50,keycompare()))
cout << "50 exists in vector";
else
cout << "50 does not exist";
cout << endl;
if (binary_search(v.begin(), v.end(), 7,keycompare() ))
cout << "7 exists in vector";
else
cout << "7 does not exist";
return 0;
}
输出
Sorted vector KEY VALUE 4 16 5 36 6 76 7 26 50 does not exist 7 exists in vector
