Getting some test case wrong answer

#1
#2

Hi @Jun18APP0112
It is giving wrong answer because you are only considering 10 primes numbers but remember that 41and many other numbers are also prime which also have to be included in finding CB number.

Optimal approach to get correct answer is :

#include
#include <bits/stdc++.h>

using namespace std;

long stoint(string s)
{
long i,j=0;
i = 0;
while(s[j] >= ‘0’ && s[j] <= ‘9’)
{
i = i * 10 + (s[j] - ‘0’);
j++;
}
return i;
}

bool is_cb_number(string s)
{
long long num = stoint(s);
if (num == 0 || num == 1) {
return false;
}
int arr[10] = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 };

    for (int i = 0; i < sizeof(arr)/sizeof(arr[0]); i++) {
        if (num == arr[i]) {
            return true;
        }
    }

    for (int i = 0; i < sizeof(arr)/sizeof(arr[0]); i++) {
        if (num % arr[i] == 0) {
            return false;
        }
    }

return true;

}

bool is_valid(bool * visited, int l, int r)
{
for(int i=l;i<r;i++)
{
if(visited[i])
{
return false;
}
}
return true;
}

int main()
{
int n;
cin>>n;
string s;
cin>>s;
long count = 0;
bool* visited = new bool[n];
for(int i=1; i <= s.length(); i++)
{
for(int j=0; j<=s.length()-i; j++)
{ int e = j+i;
string sub = s.substr(j, e-j);
if(is_cb_number(sub) && is_valid(visited,j,e))
{
count++;
for(int k=j;k<e;k++)
{
visited[k]=true;
}
}
}
}
cout<<count<<endl;
return 0;
}