C++ vector 和 array

待我称王封你为后i 2023-06-29 05:38 11阅读 0赞

#include <array>
    #include <deque>
    #include <iostream>
    #include <list>
    #include <vector>
    using namespace std;
    int main(int argc, const char *argv[]) {
        list<string> authors = {"a", "b", "c", "d"};
        deque<string> authorsList(authors.begin(), authors.end());
        for (auto obj : authorsList) {
            cout << "authorsList: " << obj << endl;
        }
        array<int, 18> a2 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17};
        auto beg = a2.begin(), end = a2.end(), begin = a2.begin();
        int sought = 11;
        auto mid   = a2.begin() + (end - beg) / 2; //二分查找 mid=beg+(end-beg)/2 与 mid=(beg+end)/2 因为假设beg和end都很大，超过了int的一半，那么beg + end可能会溢出
        while (mid != end && *mid != sought) {
            if (sought < *mid)
                end = mid;
            else
                beg = mid;
            mid = beg + (end - beg) / 2;
            cout << " mid = " << *mid << endl;
        }
        while (begin != a2.end() - 1 && *begin >= 0) {
            cout << " beg1 : " << *begin++ << ", ";
        }
        cout << endl;
        vector<string> v = {"suqsi", "simba", "frollo", "scar"};
        for (auto obj : v) {
            cout << "  >>" << obj << endl;
        }
        cout << v.capacity() << "  capacity  " << v.size() << "reserve " << endl;
        v.insert(v.begin(), {"this", "is"});
        auto begin2 = v.begin();
        while (begin2 != v.end() - 1) {
            cout << " beg2 : " << *begin2++ << ", ";
        }
        cout << endl;
        const char *ss = "0123456789";
        // s1=4,ss为字符指针在内存中占用4个字节
        int s1 = sizeof(ss);
        // s2=10,计算字符串ss的长度
        long s2    = strlen(ss);
        char str[] = "abced";
        // a为6（1*6），字符数组str包含6个元素（a,b,c,d,e,\0)，每个元素占用1个字节
        long a = sizeof(str);
        // len为5，不包含"\0"，
        long len = strlen(str);
        // str[0]是字符元素a，所以b=1
        int b = sizeof(str[0]);
        cout << "s1 sizeof " << s1 << " strlen " << s2 << endl;
        return 0;
    }