string容器
输入一行，包括空格（相当于gets）
1 #include <iostream> 2 #include <string> 3 #include <sstream> 4 using namespace std; 5 int main(){ 6 string str; 7 getline(cin,str); 8 cout<<str<<endl; 9 }
查找（指定位置的查找）转化
1 #include <iostream> 2 #include <string> 3 #include <sstream> 4 using namespace std; 5 int main(){ 6 string s; 7 stringstream ss; 8 int n, i, sum, a; 9 cin >> n; 10 getline(cin, s); // 获取换行 11 for (i=0; i<n; i++){ 12 getline(cin, s); 13 ss.clear(); 14 ss.str(s); 15 sum=0; 16 while (1){ 17 ss >> a; //逐个获取 18 if ( ss.fail() ) break; //s.fail 字符串结束 19 sum+=a; 20 } 21 cout << sum << endl; 22 } 23 string str = "aaaaddddssdfsasdf"; 24 int pos = str.find("ssdf", 3); //用if(pos == string::npos) 用来判断是否找到子串。 25 if(pos != str.npos) cout<<pos<<endl; 26 string str2 = str.substr(pos, 5); 27 cout<<str2<<endl; 28 }
转化2
1 #include <iostream> 2 #include <string> 3 #include <sstream> 4 using namespace std; 5 int main(){ 6 string s; 7 int n; 8 cin>>s; 9 stringstream ss; //stringstream ss(s); 10 ss << s; 11 cout<<ss.str()<<endl; 12 ss >> n; 13 cout<<n<<endl; 14 ss.str("");//清空stream 15 cout<<ss.str()<<endl; 16 17 string line,word[10]; 18 int x=0; 19 while(getline(cin,line)){ 20 stringstream stream(line); 21 cout<<stream.str()<<endl; // 输出stream 22 while(stream>>word[x]) x++; 23 for(int i = 0; i < x; i++) 24 cout<<word[i]<<endl; 25 } 26 }
反转
reverse 在原字符串上面反转
assign 反转到别的字符串（当然也可以复制），万能的下标（str.begin()+n,str.begin()+m）
1 #include <iostream> 2 #include <algorithm> 3 #include <string> 4 using namespace std; 5 int main(){ 6 freopen("in.txt", "r", stdin); 7 freopen("out.txt", "w", stdout); 8 string str,str2; 9 cin>>str; 10 str2.assign (str.rbegin(),str.rend()); 11 cout<<str2<<endl; 12 cout<<str<<endl; 13 reverse(str.begin(),str.end()); 14 cout<<str<<endl; 15 } 16 17 输入： asdfg 18 输出： gfdsa 19 asdfg 20 gfdsa
1 #include <iostream> 2 #include <stdio.h> 3 #include <string> 4 #include <algorithm> 5 #include <vector> 6 using namespace std; 7 int main(){ 8 //string 与 char 之间的互换 9 string str; 10 char ss[100]; 11 scanf("%s",ss); 12 str = ss; 13 printf(str.c_str()); 14 cout<<endl; 15 printf("%s ",ss); 16 cout<<str<<endl; 17 cout<<ss<<endl; 18 19 //string 与 vector的结合，相当于二维数组 20 vector <string> v; 21 v.push_back("Jack"); 22 v.push_back("Mike"); 23 v.push_back("Tom"); 24 cout<<v[0]<<endl; 25 cout<<v[1]<<endl; 26 cout<<v[2]<<endl; 27 28 string s; 29 s="12345abcde"; 30 cout<<s<<endl; 31 32 //反向排序,头文件<algorithm> 33 reverse(s.begin(),s.end()); 34 cout<<s<<endl; 35 36 //排序 37 sort(s.begin(),s.end()); 38 cout<<s<<endl; 39 40 //定义迭代器 41 string::iterator it; 42 43 //s与”1234“比较，相等返回0，小于返回-1，大于返回大于个数 44 cout<<s.compare("1234")<<endl; 45 46 //查找第一个字符‘1’，返回下标值 47 cout<<s.find('1')<<endl; 48 49 //查找第一个子串“1“，返回下标值 50 cout<<s.find("1")<<endl; 51 52 //查找第一个子串”abc“，返回下标值 53 cout<<s.find("abc")<<endl; 54 55 //查找第一个子串”abh“，查不到返回4294967295==(2^32)-1; 56 //18446744073709551615==(2^16)-1; 57 cout<<s.find("ah")<<endl; 58 59 it=s.begin(); 60 61 //从第三个开始，将连续的3个字符替换为“good” 62 //即将“45a”替换为“good” 63 s.replace(3,3,"good"); 64 cout<<s<<endl; 65 66 //把字符'p'插入到1个字符前 67 s.insert(it+1,'p'); 68 cout<<endl; 69 70 //删除第三个元素 71 s.erase(it+3); 72 cout<<s<<endl; 73 74 s.erase(it,it+3); 75 cout<<s<<endl; 76 77 s=""; 78 cout<<s<<endl; 79 cout<<s.length()<<endl; 80 81 return 0; 82 }
string find
1 #include <iostream> 2 #include <cmath> 3 using namespace std; 4 int main() 5 { 6 string str; 7 cin>>str; 8 int x=str.find("AB"),y=str.find("BA"); 9 if((x!=str.npos&&str.find("BA",x+2)!=str.npos)||y!=str.npos&&str.find("AB",y+2)!=str.npos){ 10 cout<<"YES"<<endl; 11 return 0; 12 } 13 cout<<"NO"<<endl; 14 }
substr（子串截取函数）
1 #include <iostream> 2 #include <string> 3 using namespace std; 4 int main(){ 5 string str; 6 cin >> str; 7 string str1 = str.substr(0, 3), str2 = str.substr(5, 8); 8 cout<<str1<<"**"<<str2<<endl; 9 return 0; 10 }
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