In this section we will see how to generate all possible strings of any length, this will take each combination of characters to make string. For example, if the string is ABC, then it will generate − {A, B, C, AB, BA, BC, CB, CA, AC, ABC, ACB, BAC, BCA, CAB, CBA}
Let us see the example to get the idea.
Algorithm
printAllString(str)
Begin n := length of the string str count is 2^n – 1 for each number 0 to count, do sub_str := empty string for j in range 0 to n, do if jth bit of the counter is set, then concatenate jth character of str with sub_str end if done repeat: print sub_string until next permutation of sub_string is not completed done End
Example
#include <iostream> #include <algorithm> #include <cmath> using namespace std; void printAllString(string str) { int n = str.size(); unsigned int count = pow(2, n); for (int counter = 1; counter <count; counter++) { //generate 2^n - 1 strings string subs = ""; for (int j = 0; j < n; j++) { if (counter & (1<<j)) //when the jth bit is set, then add jth character subs.push_back(str[j]); } do{ cout << subs << endl; } while (next_permutation(subs.begin(), subs.end())); } }
Output
A B AB BA C AC CA BC CB ABC ACB BAC BCA CAB CBA D AD DA BD DB ABD ADB BAD BDA DAB DBA CD DC ACD ADC CAD CDA DAC DCA BCD BDC CBD CDB DBC DCB ABCD ABDC ACBD ACDB ADBC ADCB BACD BADC BCAD BCDA BDAC BDCA CABD CADB CBAD CBDA CDAB CDBA DABC DACB DBAC DBCA DCAB DCBA