实验1现代c++初体验
实验1：
1 #include <iostream> 2 #include <string> 3 #include <vector> 4 #include <algorithm> 5 6 using namespace std; 7 8 template<typename T> 9 void output(const T &c); 10 11 void test1(); 12 void test2(); 13 void test3(); 14 15 int main() { 16 cout << "测试1: \n"; 17 test1(); 18 19 cout << "\n测试2: \n"; 20 test2(); 21 22 cout << "\n测试3: \n"; 23 test3(); 24 } 25 26 template <typename T> 27 void output(const T &c) { 28 for(auto &i: c) 29 cout << i << " "; 30 cout << endl; 31 } 32 33 void test1() { 34 string s0{"0123456789"}; 35 cout << "s0 = " << s0 << endl; 36 37 string s1{s0}; 38 reverse(s1.begin(), s1.end()); 39 cout << "s1 = " << s1 << endl; 40 41 string s2{s0}; 42 reverse_copy(s0.begin(), s0.end(), s2.begin()); 43 cout << "s2 = " << s2 << endl; 44 } 45 46 void test2() { 47 vector<int> v0{2, 0, 4, 9}; 48 cout << "v0: "; 49 output(v0); 50 51 vector<int> v1{v0}; 52 reverse(v1.begin(), v1.end()); 53 cout << "v1: "; 54 output(v1); 55 56 vector<int> v2{v0}; 57 reverse_copy(v0.begin(), v0.end(), v2.begin()); 58 cout << "v2: "; 59 output(v2); 60 } 61 62 void test3() { 63 vector<int> v0{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; 64 cout << "v0: "; 65 output(v0); 66 67 vector<int> v1{v0}; 68 rotate(v1.begin(), v1.begin()+1, v1.end()); 69 cout << "v1: "; 70 output(v1); 71 72 vector<int> v2{v0}; 73 rotate(v2.begin(), v2.begin()+2, v2.end()); 74 cout << "v2: "; 75 output(v2); 76 77 vector<int> v3{v0}; 78 rotate(v3.begin(), v3.end()-1, v3.end()); 79 cout << "v3: "; 80 output(v3); 81 82 vector<int> v4{v0}; 83 rotate(v4.begin(), v4.end()-2, v4.end()); 84 cout << "v4: "; 85 output(v4); 86 }
实验2：
1 #include <iostream> 2 #include <vector> 3 #include <string> 4 #include <algorithm> 5 #include <numeric> 6 #include <iomanip> 7 8 using namespace std; 9 10 template<typename T> 11 void output(const T &c); 12 13 int rand_int_100(); 14 void test1(); 15 void test2(); 16 17 int main() { 18 cout << "测试1: \n"; 19 test1(); 20 21 cout << "\n测试2: \n"; 22 test2(); 23 } 24 25 template <typename T> 26 void output(const T &c) { 27 for(auto &i: c) 28 cout << i << " "; 29 cout << endl; 30 } 31 32 int rand_int_100() { 33 return rand() % 101; 34 } 35 36 void test1() { 37 vector<int> v0(10); 38 generate(v0.begin(), v0.end(), rand_int_100); 39 cout << "v0: "; 40 output(v0); 41 42 vector<int> v1{v0}; 43 sort(v1.begin(), v1.end()); 44 cout << "v1: "; 45 output(v1); 46 47 vector<int> v2{v0}; 48 sort(v2.begin()+1, v2.end()-1); 49 cout << "v2: "; 50 output(v2); 51 } 52 53 void test2() { 54 vector<int> v0(10); 55 generate(v0.begin(), v0.end(), rand_int_100); 56 cout << "v0: "; 57 output(v0); 58 59 auto iter1 = min_element(v0.begin(), v0.end()); 60 cout << "最小值: " << *iter1 << endl; 61 62 auto iter2 = max_element(v0.begin(), v0.end()); 63 cout << "最大值: " << *iter2 << endl; 64 65 auto ans = minmax_element(v0.begin(), v0.end()); 66 cout << "最小值: " << *(ans.first) << endl; 67 cout << "最大值: " << *(ans.second) << endl; 68 double avg1 = accumulate(v0.begin(), v0.end(), 0)/v0.size(); 69 cout << "均值: " << fixed << setprecision(2) << avg1 << endl; 70 71 cout << endl; 72 73 vector<int> v1{v0}; 74 cout << "v0: "; 75 output(v0); 76 sort(v1.begin(), v1.end()); 77 double avg2 = accumulate(v1.begin()+1, v1.end()-1, 0)/(v1.size()-2); 78 cout << "去掉最大值、最小值之后，均值: " << avg2 << endl; 79 }
实验3：
1 #include <iostream> 2 #include <string> 3 #include <algorithm> 4 5 bool is_palindrome(std::string s); 6 7 int main() { 8 using namespace std; 9 string s; 10 11 while(cin >> s) 12 cout << boolalpha << is_palindrome(s) << endl; 13 } 14 bool is_palindrome(std::string s) 15 { 16 int l = s.size(); 17 int t = 0; 18 for(int i = 0;i<l/2;i++) 19 { 20 if(s[i] != s[l-i-1]) 21 { 22 t = 1; 23 break; 24 } 25 } 26 if(t == 0) 27 return true; 28 else 29 return false; 30 }
实验4：
1 #include <iostream> 2 #include <string> 3 #include <algorithm> 4 5 std::string dec2n(int x, int n = 2); 6 7 int main() { 8 using namespace std; 9 10 int x; 11 while(cin >> x) { 12 cout << "十进制: " << x << endl; 13 cout << "二进制: " << dec2n(x) << endl; 14 cout << "八进制: " << dec2n(x, 8) << endl; 15 cout << "十六进制: " << dec2n(x, 16) << endl << endl; 16 } 17 } 18 std::string dec2n(int x,int n) 19 { 20 char a[100000]; 21 switch(n) 22 { 23 case 2:itoa(x,a,2);break; 24 case 8:itoa(x,a,8);break; 25 case 16:itoa(x,a,16);break; 26 } 27 for(int i = 0;i<100000;i++) 28 { 29 if(a[i]=='a') 30 a[i] = 'A'; 31 if(a[i]=='b') 32 a[i] = 'B'; 33 if(a[i]=='c') 34 a[i] = 'C'; 35 if(a[i]=='d') 36 a[i] = 'D'; 37 if(a[i]=='e') 38 a[i] = 'E'; 39 if(a[i]=='f') 40 a[i] = 'F'; 41 } 42 return a; 43 }
实验5：
1 #include<iostream> 2 #include<string> 3 #include<vector> 4 #include<algorithm> 5 #include<iomanip> 6 7 using namespace std; 8 9 template<typename T> 10 void output(const T &c); 11 12 int main() 13 { 14 vector<char>v0{'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','o','v','w','x','y','z'}; 15 vector<char>v1{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','O','V','W','X','Y','Z'}; 16 cout << " "; 17 output(v0); 18 for(int i = 1;i<=26;i++) 19 { 20 vector<char>v2{v1}; 21 cout <<setw(2) << i << " "; 22 rotate(v2.begin(),v2.begin()+i,v2.end()); 23 output(v2); 24 } 25 } 26 template <typename T> 27 void output(const T &c){ 28 for(auto &i:c) 29 cout << i <<" "; 30 cout << endl; 31 }
实验6：
1 #include<iostream> 2 #include<numeric> 3 4 using namespace std; 5 6 int main() 7 { 8 int t = 0; 9 int a,b,c; 10 for(int i = 1;i<=10;i++) 11 { 12 char s = "+-*/"[rand()%4]; 13 int w = 0; 14 switch(s) 15 { 16 case '+':a = rand()%10+1;b = rand()%10+1;w = a+b;break; 17 case '-':a = rand()%10+1;b = rand()%a+1;w = a-b;break; 18 case '*':a = rand()%10+1;b = rand()%10+1;w = a*b;break; 19 case '/': 20 a = rand()%10+1; 21 for(int i = 2;i<=a;i++) 22 { 23 b = i; 24 for(int j = 1;j<=10;j++) 25 { 26 c = j; 27 if(b*c == a) 28 { 29 w = a/b; 30 break; 31 } 32 } 33 } 34 } 35 cout << a <<" " << s <<" "<< b <<" "<< "=" << " "; 36 int answer; 37 cin >> answer; 38 if(w == answer) 39 { 40 t++; 41 } 42 } 43 cout << "正确率：" << t*10 << ".00%" << endl; 44 }
收获：在本次实验报告中，对于实验4进制转换中查资料得知的itoa函数有深刻印象，可以用一行代码就实现十进制向其他进制的转换，美中不足的是转换成16进制后会是小写而非大写，得再专门转换成大写。
问题：实验6用了rand()%10+1来随机生成1-10的数字，但感觉来来回回就几道题变来变去，感觉并不是真正的随机。
