在这里，我们将看到一个与给定字符串的字母数字缩写有关的有趣问题。字符串长度小于10。我们将打印所有字母数字缩写。
字母数字缩写形式为字符与数字混合的形式。该数字的值是丢失的字符数。可能有任意多个跳过的子字符串。没有两个子字符串彼此相邻。让我们看一下获得想法的算法。
printAbbreviation(s,index,max,str)-
begin if index is same as max, then print str end if add s[index] at the last of str printAbbreviation(s, index + 1, max, str) delete last character from str count := 1 if str is not empty, then if the last character of str is a digit, then add last digit with the count value delete last character from str end if end if add count after the str printAbbreveation(s, index + 1, max, str) end
#include <iostream>
using namespace std;
void printAbbreviation(const string& s, int index, int max_index, string str) {
if (index == max_index) { //if string has ended
cout << str << endl;
return;
}
str.push_back(s[index]); // push the current character to result
printAbbreviation(s, index + 1, max_index, str); //print from next index
str.pop_back(); //remove last character
int count = 1;
if (!str.empty()) {
if (isdigit(str.back())) { //if the last one is digit, then
count += (int)(str.back() - '0'); //count the integer value of that digit
str.pop_back(); //remove last character
}
}
char to_char = (char)(count + '0'); //make count to character
str.push_back(to_char);
printAbbreviation(s, index + 1, max_index, str); //do for next index
}
void printCombination(string str) {
if (!str.length()) //if the string is empty
return;
string str_res;
printAbbreviation(str, 0, str.length(), str_res);
}
int main() {
string str = "HELLO";
printCombination(str);
}输出结果
HELLO HELL1 HEL1O HEL2 HE1LO HE1L1 HE2O HE3 H1LLO H1LL1 H1L1O H1L2 H2LO H2L1 H3O H4 1ELLO 1ELL1 1EL1O 1EL2 1E1LO 1E1L1 1E2O 1E3 2LLO 2LL1 2L1O 2L2 3LO 3L1 4O 5