c++容器内元素的问题

#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string>
#include<vector>
using namespace std;
string randArray[30]={"programming",
"pop quiz",
"assignment",
"reference drive",
"visual art",
"visual studio",
"web development",
"digital entertainment system",
"photoshop",
"maya",
"lighting",
"internet",
"computer",
"laptop",
"practical",
"lecture",
"lab group",
"tutorial",
"block m",
"array",
"pointers",
"inspiration",
"creativity",
"variables",
"potential",
"imagination",
"production"

每个容器都有它的适用范围，vector在你这里是不适用的，尽管你可以比较每个元素去实现它，但是有现成的其他容器可以使用，何必舍近求远呢
对于你这种情况， set 是最实用的。它的原理就是在容器里对于同一个元素只有一个,也就是说set里不允许有重复的元素。相反的就是multiset，它是允许重复的。

你可以用iterator遍历一下容器的内容，和输入的字母进行比较，根据比较结果决定什么操作。。。

这个问题你不是已经问过了吗，而且我也帮你解决了啊，唉，算了，再帮你写一次好了，不过我这可是给你第二次作答了：

#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string>
#include<vector>
#include<set>
using namespace std;
string randArray[30]={"programming", //declare a array that contain the 30 words
"pop quiz",
"assignment",
"reference drive",
"visual art",
"visual studio",
"web development",
"digital entertainment system",
"photoshop",
"maya",
"lighting",
"internet",
"computer",
"laptop",