题目详细内容见PTA，仅提供答案参考。
7-7 冒泡
1 #include <iostream>
2 using namespace std;
3
4 void merge(int *arr, int left, int mid, int right)
5 {
6 int n1 = mid - left + 1;
7 int n2 = right - mid;
8 int L[n1], R[n2];
9 for (int i = 0; i < n1; i++)
10 {
11 *(L + i) = *(arr + left + i);
12 }
13 for (int j = 0; j < n2; j++)
14 {
15 *(R + j) = *(arr + mid + 1 + j);
16 }
17 int i = 0, j = 0, k = left;
18 while (i < n1 && j < n2)
19 {
20 if (*(L + i) <= *(R + j))
21 {
22 *(arr + k) = *(L + i);
23 i++;
24 }
25 else
26 {
27 *(arr + k) = *(R + j);
28 j++;
29 }
30 k++;
31 }
32 while (i < n1)
33 {
34 *(arr + k) = *(L + i);
35 i++;
36 k++;
37 }
38 while (j < n2)
39 {
40 *(arr + k) = *(R + j);
41 j++;
42 k++;
43 }
44 }
45
46 void mergeSort(int *arr, int left, int right)
47 {
48 if (left < right)
49 {
50 int mid = (left + right) / 2;
51
52 mergeSort(arr, left, mid);
53 mergeSort(arr, mid + 1, right);
54
55 merge(arr, left, mid, right);
56 }
57 }
58
59 int main()
60 {
61 int n;
62 cin >> n;
63 int a[n];
64 for (int i = 0; i < n; i++)
65 {
66 cin >> *(a + i);
67 }
68 mergeSort(a, 0, n - 1);
69 for (int i = 0; i < n; i++)
70 {
71 cout << *(a + i) << " ";
72 }
73 cout << endl;
74 return 0;
75 }
7-8 在数组中查找指定元素
#include <iostream>
using namespace std;
class NotFoundException : public exception
{
public:
virtual const char* what() const throw()
{
return "Not found";
}
};
class InvalidInputException : public exception
{
public:
virtual const char* what() const throw()
{
return "Invalid input";
}
};
class Search
{
public:
Search() {}
~Search() {}
int search(int* list, int n, int x)
{
if (list == NULL || n <= 0)
throw InvalidInputException();
for (int i = 0; i < n; i++)
{
if (list[i] == x)
return i;
}
throw NotFoundException();
}
void inputArray(int* a, int n)
{
for (int i = 0; i < n; i++)
{
cin >> a[i];
}
}
void run()
{
int repeat;
cin >> repeat;
while (repeat--)
{
int n, x;
cin >> n;
try {
if (n <= 1 || n > 10)
throw InvalidInputException();
int a[n];
inputArray(a, n);
cin >> x;
int res = search(a, n, x);
printf("index = %d\n", res);
}
catch (NotFoundException& e)
{
cout << e.what() << endl;
}
catch (InvalidInputException& e)
{
cout << e.what() << endl;
}
catch (exception& e)
{
cout << "Unknown exception." << endl;
}
}
}
};
int main()
{
Search s;
s.run();
return 0;
}
7-9 使用函数删除字符串中的字符
#include <iostream>
#include <cstring>
using namespace std;
void delchar(char* str, char c)
{
int i = 0, j = 0;
int len = strlen(str);
while(i < len)
{
if(str[i] != c)
{
str[j++] = str[i];
}
i++;
}
str[j] = '\0';
}
int main()
{
int repeat;
cin >> repeat;
while(repeat<=0 || repeat>=10)
{
cin >> repeat;
}
for(int i=0; i<repeat; i++)
{
char str[100];
cin >> str;
int len = strlen(str);
while(len>100)
{
cin >> str;
len = strlen(str);
}
char c;
cin >> c;
delchar(str, c);
cout << "result: " << str << endl;
}
return 0;
}
7-10 使用函数实现字符串复制
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
void strmcpy(string &s, const string &t, int m)
{
s.resize(0);
if (m <= t.size())
{
copy(t.begin() + m - 1, t.end(), back_inserter(s));
}
else
{
s = "error input";
}
}
int main()
{
int repeat;
cin >> repeat;
while (repeat--)
{
string t, s;
int m;
cin >> t >> m;
strmcpy(s, t, m);
cout << s << endl;
}
return 0;
}
7-11 找最大的字符串
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
using namespace std;
int main()
{
vector<string> str(5);
for (auto& s : str)
{
cin >> s;
}
auto max_str = *max_element(str.begin(), str.end());
cout << "Max is: " << max_str << endl;
return 0;
}
7-6 组织星期信息
#include <iostream>
#include <string>
#include <unordered_map>
using namespace std;
int main()
{
int repeat;
cin >> repeat;
unordered_map<string, int> weeks = {
{"Sunday", 1}, {"Monday", 2}, {"Tuesday", 3},
{"Wednesday", 4}, {"Thursday", 5}, {"Friday", 6}, {"Saturday", 7}
};
while (repeat--)
{
string str;
cin >> str;
int index = weeks.find(str) == weeks.end() ? -1 : weeks[str];
cout << index << endl;
}
return 0;
}
7-12 查找奥运五环色的位置
#include <iostream>
#include <unordered_map>
using namespace std;
int main()
{
unordered_map<string, int> colors = {
{"red", 1},
{"blue", 2},
{"yellow", 3},
{"green", 4},
{"black", 5}
};
string input_color;
getline(cin, input_color);
if (auto it = colors.find(input_color); it != colors.end())
{
cout << it->second << endl;
}
else
{
cout << "Not Found" << endl;
}
return 0;
}
7-5 实数排序
#include <iostream>
#include <vector>
#include <algorithm>
#include <iomanip>
using namespace std;
int main()
{
int n;
cin >> n;
vector<double> nums(n);
for (auto &num : nums)
{
cin >> num;
}
sort(nums.begin(), nums.end(), greater<double>());
for (int i = 0; i < n - 1; i++)
{
cout << fixed << setprecision(2) << nums[i] << " ";
}
cout << fixed << setprecision(2) << nums[n - 1] << endl;
return 0;
}
7-13 字符串的连接
#include <iostream>
#include <string>
using namespace std;
int main()
{
string s1, s2;
getline(cin, s1);
getline(cin, s2);
for (char c : s2)
s1 += c;
cout << s1 << endl;
return 0;
}
标签：SYNU,cout,int,cin,PTA,repeat,C++,str,include From： https://www.cnblogs.com/Elysia1111/p/17231664.html