Getting wrong answer in the problem code:PERMUT2

i am getting wrong answer in the problem ambiguous permutations but i think my code is correct and even in codeblocks it is giving correct output.
please help me to find to out what is wrong.

below is the link to code:

https://www.codechef.com/viewsolution/35872121

n can be as big as 10^5. You cannot store such a big length number in int. You can maybe use a string and just append the number as a character.

But an easier was to do this would be:

	int n;
	cin >> n;
	int A[n], B[n];
	for(int i = 0; i < n; i++) {
		cin >> A[i];
		A[i]--;
		B[A[i]] = i;
	}
	bool ok = 0;
	for(int i = 0; i < n; i++) {
		if(A[i] != B[i])
			ok = 1;
	}
	cout << (ok ? "not ambigous\n" : "ambigous\n");

You code will only work for n < 10, after which there will be overflows. You cannot represent 11 digit numbers (or larger) in datatype int.

3 Likes

but if i am not assigning the array size first and then getting it assigned after cin>>t, thenalso it is showing wrong answer

below is the updated code

#include<iostream>
#include<math.h>
using namespace std;
int main()
{
    int t,orig=0,raise;

    while(1){
        orig=0;

        cin>>t;
        int a[t];
        if(t==0) break;
        raise=t;
        for(int i=0;i<t;i++)
        { //input
            cin>>a[i];
            orig+=a[i]*pow(10,--raise);
        }

        int total=0,power=t;

        for(int j=1;j<=t;j++){ //reverse number storage loop

        int count=0;

        for(int i=0;i<t;i++){ //checking of the place loop

            count++;
            if(j==a[i])
            {
                break;
            }
        }

        total=total+count*pow(10,--power);
           //storing reverse value
        }

        if(total==orig) {cout<<"ambiguous"<<endl;}
        else{cout<<"not ambiguous"<<endl;}
    }
    return 0;
}

I am taking about your orig. It has n digits. And an int can only have 9 digits. So when n > 10, you have overflow in orig.


Add this optimization flag to detects overflows.

3 Likes

ohh , i got it , now i undertood why my code getting wrong answer.
thank you sooo much for the help.

1 Like