STL Vector 사용법

#include <bits/stdc++.h>
using namespace std;
//STL vector
int main()
{
    vector<int> vec;
    vector<int> vec1(10);
    vector<int> vec2(40, 3); 


    vec.push_back(5);
    vec.push_back(3);
    vec.push_back(1);
    vec.insert(vec.begin(), 2);

    for(vector<int>::iterator itr=vec.begin(); itr!=vec.end(); itr++){
        if(*itr == 3){
            vec.insert(itr, 77);
            break;
        }
    }

    printf("\n");
    for(auto x : vec){
        printf("%d ", x);
    }


    vec.pop_back();
    vec.erase(vec.begin());
    printf("\n");
    for(auto x : vec){
        printf("%d ", x);
    }

    printf("\nsize :%d fron :%d rear: %d", vec.size(), vec.front(), vec.back());


    vec.assign(5, 4);
    printf("\n");
    for(auto x : vec){
        printf("%d ", x);
    }

    vec.clear();
    vec = vector<int>();
    printf("\n");
    for(auto x : vec){
        printf("%d ", x);
    }
    return 0;
}