How i can get all substring of size k of string?-CodePudding

I don't know where is the error in my code ? can someone help me to fix it .

My code :

#include<bits/stdc  .h>
using namespace std;
#define ll long long
void solution() {
   string s;
   ll k;
   cin >> s >> k;
   for(int i=0; i<=s.length()-k; i  ) {
       for(int r=k-1; r<s.length(); r  ){
           cout << s.substr(i,r) << endl;
       }
   }
}
int main() {
    ll t;
    cin >> t;
    while(t--){
         solution();
    }
    return 0;
}

input :

1
ABCD 3

Expected output:

ABC
BCD

Actual output:

AB
ABC
BC
BCD

CodePudding user response：

I have no idea why you need a nested for loop. Why isn't this just simply:

void solution() {
   string s;
   ll k;
   cin >> s >> k;

   for(int i = 0; i <= s.length() - k; i  ) {
     cout << s.substr(i, k) << endl;
   }
}

CodePudding user response：

Here's a way to get all substring with the length given:

#include<string>
#include<iostream>

int main() {
    int input = 0;
    std::string str = "";
    std::cin >> input >> str;    //This is the length of substring you wanna get
    for (int i = str.size() - input; i >= 0; i--){
        std::cout << str.substr(i, input) << " ";    //output the result from end to begin
    }
}

You will get a decreasing-order answer.