How to check whether element of vector is same?

[comebackkid]

How to check if a container of a vector have same element?
for example: a vector is contained with employee and task. i want to sort all the task by the name of employee.

[TwilightSpectre]

I'm not entirely sure what you mean, but you could use the standard algorithms:

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

struct Data {
    std::string employee;
    std::string task;
};

int main() {
    std::vector<Data> employees {
        { "Bob", "Nothing" },
        { "James", "Sleep" },
        { "Alice", "Eat" },
        { "Fred", "Roll on floor" }
    };

    std::sort(employees.begin(), employees.end(),
        [](const Data& a, const Data& b){ return a.employee < b.employee; });

    for (const auto& x : employees)
        std::cout << x.employee << "\t: " << x.task << "\n";
    
    return 0;
}

[comebackkid]

thanks man.