请实现一个函数,把字符串中的每个空格替换成“%20”,例如:we are family——》we%20are%20family.
1 #include<iostream> 2 #include<string> 3 using namespace std; 4 int main() 5 { 6 string str; 7 getline(cin, str); 8 int len = str.size(); 9 int count = 0; 10 for (int i = 0; i < len; i++) 11 { 12 if (str[i] == ' ') 13 count++; 14 } 15 count = count * 2; 16 str.append(count, '\0'); 17 int j = len + count-1; 18 for (int i = len - 1; i >= 0; i--) 19 { 20 if (str[i] == ' ') 21 { 22 str[j] = '0'; 23 str[j - 1] = '2'; 24 str[j - 2] = '%'; 25 j = j - 3; 26 } 27 else 28 { 29 str[j] = str[i]; 30 j--; 31 } 32 } 33 cout << str << endl; 34 system("pause"); 35 return 0; 36 }