c++ primer 练习 3.24、3.25、3.26

3.24

1

#include<iostream>
using std::cin;
using std::cout;
using std::endl;
#include<vector>
using std::vector;int main()
{
int temp;
vector<int> v;
while(cin >> temp) {
v.push_back(temp);
}
// 用迭代器遍历、访问元素
for(auto it = v.cbegin();
it != v.cend() - 1; ++it) {
cout << *it + *(it + 1) << endl;
}
return 0;
}

2
#include<iostream>
using std::cin;
using std::cout;
using std::endl;
#include<vector>
using std::vector;int main()
{
int temp;
vector<int> v;
while(cin >> temp) {
v.push_back(temp);
}
// 用迭代器遍历、访问元素
auto head = v.cbegin();
auto tail = v.cend() - 1;
for( ; head <= tail; ++head, --tail) {
cout << *head + *tail << endl;
}
return 0;
}
3.25
#include<iostream>
using std::cin;
using std::cout;
using std::endl;
#include<vector>
using std::vector;
int main()
{
vector<unsigned> score(11, 0);
unsigned grade;
auto ind = score.begin();
while (cin >> grade) {
if (grade <= 100)
++*(ind + grade/10);
}
for (auto i: score) {
cout << i << endl;
}
return 0;
}

3.26
迭代器间不支持加法运算。（参考99页）