This code is supposed to return yes if the string has 'nadia' no otherwise. But when I submitted it said wrong answer although it is wokring on the sample tests.? Does anyone know what I am missing?
#include<iostream>
#include<string>
#include<vector>
using namespace std;
int main()
{
int t;
bool flag = false;
bool flag2 = false;
bool flag3 = false;
bool flag4 = false;
int count = 0;
vector<string>v;
cin >> t;
string x;
for (int i = 0; i < t; i++)
{
cin >> x;
v.push_back(x);
}
for (int i = 0; i < v.size(); i++)
{
x = v[i];
for (int i = 0; i < x.length(); i++)
{
if (x.at(i) == 'n')
{
flag = true;
for (int i = 0; i < x.length(); i++)
{
if (x.at(i) == 'a')
{
++count;
flag2 = true;
for (int i = 0; i < x.length(); i++)
{
if (x.at(i) == 'd')
{
flag3 = true;
for (int i = 0; i < x.length(); i++)
{
if (x.at(i) == 'i')
{
flag4 = true;
}
}
}
}
}
}
}
}
if ((flag) && (flag2) && (flag3) && (flag4) && (count >= 2))
{
cout << "YES" << endl;
}
else
{
cout << "NO" << endl;
}
count = 0;
flag = false;
flag2 = false;
flag3 = false;
flag4 = false;
}
system("pause");
return 0;
}
Sample Input:
3
anhaldillooa
nnaaddiiaa
nxzdiao
Sample Output:
YES
YES
NO
You're almost building a state machine just to find substrings.
Try std::string::find
std::string str ("There are two needles in this haystack with needles.");
std::string str2 ("needle");
// different member versions of find in the same order as above:
std::size_t found = str.find(str2);
if (found!=std::string::npos)
std::cout << "first 'needle' found at: " << found << '\n';
A alternative to your code with only on for loop:
bool contains(string input, string target){
int target_index = 0;
for(int i = 0; i < input.size(); i++){
target_index = input.at(i) == target[target_index].at(i) ? target_index + 1 : 0;
if(target_character_index + 1 == target.size()) return true;
}
return false;
}
int main()
{
int size = 0;
cin>>size;
string target = "nadia";
while(size-- > 0){
string input = "";
cin>>input;
cout>>contains(input, target) ? "YES" : "NO";
}
return 0;
}
All of your loops start with i = 0.
That means you're just looking for the characters n, a, d, i and a, individually, anywhere in the string, with no relation to where the other desired characters are found.
You're not doing a substring search at all. This is simply the wrong algorithm.
You also only tested inputs with "nadia" all found in a row; if you'd tested e.g. "diana" as well, you'd have discovered the false positive result that was undoubtedly triggered by the online testing program.
Related
In this question, we take 2 strings as input say s1 and s2.
Now, first we need to check if s2 is a subsequence of s1. If not, print no.
But if it is, we need to print the minimum number of characters to be deleted from s1 to get s2.
Eg- thistext text
Here, text can be directly found without deleting any characters so the answer is 0.
Eg- cutefriendship crisp
In this case, the answer is 9.
What I've done so far,
#include <bits/stdc++.h>
using namespace std;
int checkIfSub(string s1, string s2, int m, int n)
{
int j = 0;
for(int i = 0; i < m && j < n; i++)
if(s1[i] == s2[j])
j++;
if(j == n)
return 0;
else
return 1;
}
int check(string s1, string s2)
{
int count = 0; string s3;
if(checkIfSub(s1, s2, s1.length(), s2.length()) == 1 || s2.length() > s1.length())
{
cout << "NO\n"; return 0;
}
int j = 0;
for(int i = 0; i < s1.length(); i++)
{
if(s1[i] == s2[j])
{
s3[j] = s1[j];
j++; continue;
}
count++;
}
cout << "YES " << count << "\n";
return 0;
}
int main() {
string s1, s2;
cin >> s1 >> s2;
check(s1, s2);
return 0;
}
My code works well for the second example, but fails the first case.
(This was a question asked in some interview I read online.)
Try something like this:
#include <iostream>
#include <string>
using namespace std;
bool check(const string &s1, const string &s2, int &minToDelete)
{
minToDelete = 0;
bool anySubSeqFound = false;
if (s2.empty())
return false;
string::size_type first = 0;
while ((first = s1.find(s2[0], first)) != string::npos)
{
int numDeleted = 0;
bool isSubSeq = true;
string::size_type next = first + 1;
for(string::size_type j = 1; j < s2.size(); ++j)
{
string::size_type found = s1.find(s2[j], next);
if (found == string::npos)
{
isSubSeq = false;
break;
}
numDeleted += (found - next);
next = found + 1;
}
if (isSubSeq)
{
if (anySubSeqFound)
{
if (numDeleted < minToDelete)
minToDelete = numDeleted;
}
else
{
anySubSeqFound = true;
minToDelete = numDeleted;
}
}
++first;
}
return anySubSeqFound;
}
int main()
{
int minToDelete;
if (check("thistext", "text", minToDelete))
cout << "yes, delete " << minToDelete << endl;
else
cout << "no" << endl;
if (check("cutefriendship", "crisp", minToDelete))
cout << "yes, delete " << minToDelete << endl;
else
cout << "no" << endl;
}
Live Demo
Write a program that uses the function isPalindrome given in Example 6-6 (Palindrome). Test your program on the following strings:
madam, abba, 22, 67876, 444244, trymeuemyrt
Modify the function isPalindrome of Example 6-6 so that when determining whether a string is a palindrome, cases are ignored, that is, uppercase and lowercase letters are considered the same.
The isPalindrome function from Example 6-6 has been included below for your convenience.
bool isPalindrome(string str)
{
int length = str.length();
for (int i = 0; i < length / 2; i++) {
if (str[i] != str[length – 1 – i]) {
return false;
} // if
} // for loop
return true;
}// isPalindrome
Your program should print a message indicating if a string is a palindrome:
madam is a palindrome
My program so far is this
#include <iostream>
#include <string.h>
using namespace std;
int main () {
bool isPalindrome (string str);
string str;
int length = str.length();
cout << "Enter a string: ";
getline (cin,str);
for (int i = 0; i < length / 2; i++) {
if (str[i] != str[length -1 -i]) {
cout << str << "Is not a Palindrome";
return false;
} else if (str[i] == str[length -1 -i] && toupper(str[i]) != islower(str[i])) {
cout << str << "Is a Palindrome";
} // for loop
return true;
}
}
I do not know what im doing wrong I sent everything to make sure it matches the word backwards and then when it is true it will return true. I am very to new to programming and I am sorry if my code is a little sloppy.
This is a modification of your code. It wasn't too logical that you were declaring the function inside so i just put it outside.
#include <iostream>
#include <string.h>
using namespace std;
bool isPalindrome(string str) {
int length = str.length();
for (int i = 0; i < length / 2; i++) {
if (str[i] != str[length -1 -i]) {
cout << str << "Is not a Palindrome";
return false;
} else if (str[i] == str[length -1 -i] && toupper(str[i]) != islower(str[i])) {
cout << str << "Is a Palindrome";
} // for loop
return true;
}
return false;
}
int main () {
string str;
cout << "Enter a string: ";
getline (cin,str);
isPalindrome(str);
}
public static bool IsPalindrome(string value)
{
int i = 0;
int j = value.Length - 1;
while (true)
{
if (i > j)
{
return true;
}
char a = value[i];
char b = value[j];
if (char.ToLower(a) != char.ToLower(b))
{
return false;
}
i++;
j--;
}
}
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#define MAX 1000
bool isPalindrome(int x){
int c[MAX];
int i = 0;
int j;
int k = 0;
bool z;
if(x < 0){
return false;
}
while (x != 0){
int r = x % 10;
c[i] = r;
i++;
x = x / 10;
}
for (j = i - 1; j > -1; j--) {
printf("%d ", c[j]);
}
for(k = 0; k <= (i / 2); k++){
if(c[k] == c[i - k - 1]){
z = true;
}
else
{
z = false;
}
}
return z;
}
I cant get the char search to work. The substring function is working but the char search won't provide the right location of the char it is looking for
#include<iostream>
#include <string>
using namespace std;
int charsearch(string searchInto, char ch, int start = 0)
{
int x = 0;
long n = searchInto.length();
for (int i = 1; i < n; i++)
{
cout << ch;
if (searchInto[i] == ch)
{
i = x;
}
else
i++;
}
cout<< x;
return x;
}
int substr(string src, string tosearch, int start = 0)
{
string searchInto = src;
long n = searchInto.size();
long m = tosearch.size();
int ans = -1;
for (int i = start; i < n; ++i)
{
int p = i;
int q = 0;
bool escape = false;
while (p < n && q < m) {
if (searchInto[p] == tosearch[q]) {
if (tosearch[q] == '/' && !escape) {
++q;
} else {
++p; ++q;
}
escape = false;
} else if (!escape && tosearch[q] == '*') {
++q;
while (q < m && p < n && searchInto[p] != tosearch[q]) ++p;
escape = false;
} else if (!escape && tosearch[q] == '?') {
++p; ++q;
escape = false;
} else if (tosearch[q] == '/' && !escape) {
escape = true;
++q;
} else break;
}
if (q == m) {
return i;
}
if (q == m - 1 && tosearch[q] == '*') {
if (q > 0 && tosearch[q - 1] == '/') continue;
else return i;
}
}
return ans;
}
int main()
{
string searchInto, tosearch;
cout<< "Enter string:";
getline(cin, searchInto);
cout << "Looking for :";
getline(cin, tosearch);
if (tosearch.length() < 2)
{
char ch = tosearch.at(0);
cout << "Found at: " <<charsearch(searchInto, ch) << endl;
cout << "Used Char" << endl;
}
else
cout << "Found at: " <<substr(searchInto, tosearch) << endl;
return 0;
}
To find a character in a string, you have two interfaces.
std::string::find will return the position of a character you find:
auto pos = yourStr.find('h');
char myChar = yourStr[pos];
If the character does not exist, then std::string::npos will be returned as the std::size_t returned for position.
stl algorithm std::find, in header algorithm returns an iterator:
auto it = std::find(yourStr.begin(), yourStr.end(), 'h');
char myChar = *it;
If the character does not exist, then it == yourStr.end().
There are some silly mistakes in your CharSearch method. First of all, You have to break the loop when you got your target character. And most importantly you are not assigning x when you are finding the target. Furthermore, there is extra increment of value i inside the loop. I have modified the function. Please check it below
int charsearch(string searchInto, char ch, int start = 0) {
int x = -1;
long n = searchInto.length();
for (int i = start; i < n; i++)
{
cout << ch;
if (searchInto[i] == ch)
{
x = i; // previously written as i = x which is wrong
break; // loop should break when you find the target
}
}
cout<< x;
return x;
}
Please note that,you can either also use find method of string or std::find of algorithm to search in string.
You need to make changes as per this code
int charsearch(string searchInto, char ch, int start = 0)
{
int x = -1; // : change, if return -1, means not found
long n = searchInto.length();
for (int i = start; i < n; i++) // : change
{
cout << ch;
if (searchInto[i] == ch)
{
x = i; // : change
break; // : change
}
}
cout<< x;
return x;
}
Note : This function will return 1st match.
I've a task to count the occurrences of sub string in a char String. I write this code but on certain inputs output is wrong. like string is "hassana" and sub is "as" then it outputs 2 ...some one plz help me
int CharString :: countOccurenceOf(const char* substr)
{
int count = 0;
bool find = false;
for(int i = 0; i < size1; i++)
{
if(cstr[i] == substr[0])
{
int x = i;
int c = 1;
find = true;
while ( substr[c] != '\0' && find == true && (x+1) < size1)
{
if(cstr [x+1] != substr[c])
{
find = false;
}
c++;
x++;
}
if (find == true)
{
count++;
i = i + c-1;
}
}
}
return count;
}
Got some Solution.....is that okay?
int CharString :: countOccurenceOf(const char* substr)
{
int len = 0;
if ( substr != '\0')
{
while( substr[len] != '\0')
len++;
}
int count = 0;
bool find = false;
for(int i = 0; i < size1; i++)
{
if(cstr[i] == substr[0])
{
int x = i;
int c = 1;
find = true;
while ( substr[c] != '\0' && find == true && (x+1) < size1)
{
if(cstr [x+1] != substr[c])
{
find = false;
}
c++;
x++;
}
if (find == true && c == len)
{
count++;
i = i + c-1;
}
}
}
return count;
}
The problem is that you're breaking automatically if x+1 < size1. If the first character of the substring matches the last character of the main string, then this will automatically break and "find" will still be set to true so you'll increment matches by 1. There are numerous ways to change your code to fix this problem; hopefully you can find one now that you know what the problem is.
Assuming cstr is your class internal string:
int CharString :: countOccurenceOf(const char* substr)
{
int occurrencies = 0;
unsigned char* s = cstr;
while (s) {
if (strstr(s,substr)) { occurrencies++; s+= strlen(substr); }
else s++;
}
return occurrencies;
}
Given 2 strings, design a function that can check whether they are rotations to each other without making any changes on them ? The return value is boolean.
e.g ABCD, ABDC, they are not rotations. return false
ABCD, CDAB or DABC are rotations. return true.
My solution:
shift one of them to right or left one position and then compare them at each iteration.
If they are not equal at all iterations, return false. Otherwise, return true.
It is O(n). Are there other more efficient solutions ?
What if the contents of them cannot be changed ?
thanks
Concatenate the given string with the given string.
Search for the target string in the concatenated string.
Example:
Given = CDAB
After step 1, Concatenated = CDABCDAB
After step 2, Success CDABCDAB
^^^^
Rather than shifting one of them, it might be more efficient to use two index variables. Start one at 0 each time and the other at each of the possible positions (0 to N-1) and increment it mod N.
If you can't modify the strings, just take the first character of string1 and compare it to each character of string2. When you get a match, compare the second char of string1 to the next char of string2, and so on.
Pseudocode:
len = strlen(string1);
len2 = strlen(string2);
if( len != len2 )
printf("Nope.");
for( int i2=0; i2 < len; i2++ ) {
for( int i1=0; i1<len; i1++ ) {
if( string1[i1] != string2[(i2+i1)%len] )
break;
}
if( i1 == len ) {
print("Yup.");
break;
}
}
A simple one would be:
(s1+s1).find(s2) != string::npos && s1.size() == s2.size();
#include <iostream>
#include <cstring>
#include<string>
using namespace std;
void CompareString(string, string, int);
int ComputeStringLength(string str);
int main()
{
string str = ""; string str1 = ""; int len = 0, len1 = 0;
cout << "\nenter string ";
cin >> str;
cout << "\nenter string 2 to compare:- ";
cin >> str1;
len = ComputeStringLength(str);
len1 = ComputeStringLength(str1);
if (len == len1)
CompareString(str, str1, len);
else
cout << "rotation not possible";
getchar();
return 0;
}
int ComputeStringLength(string str)
{
int len = 0;
for (int i = 0; str[i] != '\0'; i++)
{
len++;
}
return len;
}
void CompareString(string str, string str1, int n)
{
int index = 0, flag = 0, curr_index = 0, count1 = 0, flagj = 0;
for (int i = 0; i<n; i++)
{
for (int j = flagj; j<n; j++)
{
if (str[i] == str1[j])
{
index = j;
flagj =j;
count1++;
flag++;
if (flag == 1)
{
curr_index = index;
}
break;
}
}
}
int temp = count1;
if (count1 != n)
{
if (curr_index>=0)
{
int k = 0;
for (int i = n - 1; i>n - curr_index - 1; i--)
{
if (str[i] == str1[k])
{
temp++;
k++;
}
}
}
if (temp == n)
{
cout << "\n\nstring is same after rotation";
}
else
{
cout << "\n\nstring is not same after rotation";
}
}
else
{
cout << "\n\nstring is same after rotation";
}
}
https://dsconceptuals.blogspot.in/2016/10/a-program-to-check-if-strings-are.html