Codeforces problem 373A-http://codeforces.com/problemset/problem/373/A
Instead of multiple if statements for counting number of elements of each number,I have tried to check for given condition after sorting the array.I am getting incorrect output for 1st test case(given in the link for the problem).What is wrong with my approach?What should I change in my solution.
My solution:
#include<iostream>
#include<cstring>
using namespace std;
int k,i,j,a;
char panel[17],temp,output[4];
int main()
{
cin>>k;
for(i=0;i<16;i++)
cin>>panel[i];
for(i=0;i<16;i++) //Bubble sort.
{
for(j=0;j<(15-i);j++)
{
if(panel[j]>panel[j+1])
{
temp=panel[j+1];
panel[j+1]=panel[j];
panel[j]=temp;
}
}
}
a=1;
strcpy(output,"YES");
for(i=0;i<16;i++)
{
if(panel[i]==panel[i+1])
++a;
else
a=1;
if(a>(2*k));
{
strcpy(output,"NO");
break;
}
}
cout<<output;
}
You have a semi-colon after the if statement:
if(a>(2*k));
That means, it's always going copy "NO" and break the loop. Remove it.
Related
#include <iostream>
#include <string.h>
using namespace std;
class sorting
{
private:
char str[10];
public:
sorting() {
int i;
for(i=0;i<10;i++) {
cin>>str[i];
}
}
void sort() {
int i,j;
char temp;
for(i=0;i<10;i++) {
for(j=i+1;j<10;j++) {
if(strcmp(str[j],str[j+1])>0) {
strcpy(temp,str[j]);
strcpy(str[j],str[j+1]);
strcpy(str[j+1],temp);
}
}
}
for(i=0;i<10;i++) {
cout<<str[i];
cout<<"\n";
}
}
};
int main() {
sorting s1;
cout<<s1.sort();
return 0;
}
This is a code I have written to sort strings using constructors. It gives me error in the if condition of the code where I have used strcmp. Please review this for I could not get the desired output and it gives me errors.
Problem 1
Like someone already pointed out, you cant use strcopy on chars. If you want to create a string array i would suggest using either char** or std::string*.
Problem 2
In your nested loop you will get an index out of bounds error, due to the fact that once i reaches a value of 8, j will be 9, which means that when you try to access str[j+1] which evaluates to str[10], you will get said error.
I am facing difficulty while solving a problem where we have to check whether a string is a subsequence of another string or not.
A man with name M is allowed to marry a woman with name W, only if M is a subsequence of W or W is a subsequence of M.
A is said to be a subsequence of B if A can be obtained by deleting some elements of B without changing the order of the remaining elements.
Example -
john and johanna will give "YES" as output
kayla and jayla will give "NO" as output
johanna and john will give "YES" as output
My code is :
#include <iostream>
#include<string>
using namespace std;
bool checksub(string a, string b)
{
int pos=0;
for(int i=0; i<a.size(); i++)
{
int flag=0;
for(int j=pos; j<b.size(); j++)
{
if(b[j]==a[i])
{
flag=1;
pos=j;
break;
}
}
if(flag==0)
{
return false;
}
}
return true;
}
int main() {
// your code goes here
int t;
cin>>t;
while(t--)
{
string a,b;
cin>>a>>b;
if(a.size()==b.size())
{
if(a==b)
{
cout<<"YES"<<endl;
}else{
cout<<"NO"<<endl;}
}
else if(a.size()>b.size()){
if(checksub(b,a))
{
cout<<"YES"<<endl;
}else{
cout<<"NO"<<endl;
}
}else{
if(checksub(a,b))
{
cout<<"YES"<<endl;
}else{
cout<<"NO"<<endl;
}
}
}
return 0;
}
The editorial of the question uses a similar approach. Can anybody tell me what's wrong with my code?
The editorial solution is given below :
#include <cstdio>
char M[25005], W[25005];
bool contains(const char *A, const char *B){
while(*A){
if(*B==*A)
B++;
A++;
}
return !*B;
}
int main(){
int T;
scanf("%d", &T);
while(T--){
scanf("%s %s", M, W);
puts(contains(M, W) || contains(W, M) ? "YES" : "NO");
}
return 0;
}
Link to the problem: https://www.codechef.com/problems/NAME2
Your code produces the wrong result with input AA BAB because it fails to account for the fact that you need to have two A in the second string.
You might be able to fix it by changing pos=j; to pos=j+1; but I'm not certain.
There really is no similarity between your code and the editoral code however. Even with my suggested fix (if it does work) your code is clearly less efficient than the editorial code because it scans the input strings repeatedly.
Got the correct answer just by changing pos=j+1 instead of pos=j. Then code will become similar to the pseudocode in the editorial. Thanks, everybody for answering.
I have been debugging and seeing this code for nearly a week now still I couldn't find any solution and thus hoping to get one from the fellow developers in stack overflow.
This is the solution of the Faded Palindrome problem of September Challenge Codechef This is the problem page
#include<iostream>
#include<vector>
#include<iterator>
#include<stdlib.h>
#include<cstdio>
#include<string>
using namespace std;
string def="-1";
int main()
{
int t;
cin>>t;
//vector<string> out(t);
string out[100];
for(int i=0;i<t;i++)
{
string inp;
cin>>inp;
if(inp.size()%2) //Checking wether the number of letters is odd
{
int counter=inp.size()/2;
int counter_back=counter-1;
int counter_front=counter+1;
if(inp[counter]=='.')
inp[counter]='a';
int not_fa=0;
while(counter_back>=0&&counter_front<inp.size())
{
if(inp[counter_back]==inp[counter_front])
{counter_back--;counter_front++;}
else if(inp[counter_back]=='.'&&inp[counter_front=='.']){
inp[counter_back]=inp[counter_front]='a';
counter_back--;counter_front++;
}
else if(inp[counter_back]=='.'){
inp[counter_back]=inp[counter_front];
counter_back--;counter_front++;
}
else if(inp[counter_front]=='.'){
inp[counter_front]=inp[counter_back];
counter_back--;counter_front++;
}
else{
not_fa=1;
break;
}
}
if(not_fa)
out[i]=def;
else
out[i]=inp;
}
else{ //Checking the number of letter is even
//cout<<inp.size();
int counter_front=(inp.size())/2;
//cout<<counter_front;
int counter_back=counter_front-1;
//cout<<counter_back;
int not_fa=0;
while(counter_back>=0&&counter_front<inp.size())
{
if(inp[counter_back]==inp[counter_front])
{//cout<<"*-";
counter_back--;counter_front++;}
else if(inp[counter_back]=='.'&&inp[counter_front]=='.'){
inp[counter_back]=inp[counter_front]='a';
counter_back--;counter_front++;
}
else if(inp[counter_back]=='.'){
//cout<<"--";
inp[counter_back]=inp[counter_front];
counter_back--;counter_front++;
}
else if(inp[counter_front]=='.'){
inp[counter_front]=inp[counter_back];
counter_back--;counter_front++;
}
else{
not_fa=1;
break;
}
}
if(not_fa)
out[i]=def;
else
out[i]=inp;
}
}
/*vector<string>::iterator itr;
for(itr=out.begin();itr!=out.end();itr++)
cout<<*itr<<endl;*/
for(int j=0;j<t;j++)
if(j==t-1)
cout<<out[j];
else
cout<<out[j]<<"\n";
return 0;
}
While your code may pass all the test cases presented in the problem statement, there are still more edge cases that your code doesn't cover. Here's a sample test case:
6
..
...
..e
a..a.v.
p..p
t.xzt
This should print:
aa
aaa
eae
avaaava
paap
tzxzt
instead it prints:
..
.a.
aaa
aa.a.aa
p..p
taxat
Hints:
The first if statement is not correctly handling the case where inp[b] and inp[f] are both '.'.
There is no need for doing two different things when |s| is even or odd.
Also, in the first else if statement, you probably meant inp[counter_front]=='.' instead of inp[counter_front=='.'].
if(inp[counter_back]==inp[counter_front]) is true if they both are equal to '.' so you won't fill that gap.
Here is the link for the problem: http://www.spoj.com/problems/STAMPS/;
here is the ideone link for the current code: http://ideone.com/AcHfc6;
here is the code:
#include <iostream>
#include <stdio.h>
#include <algorithm>
using namespace std;
int main()
{
int t,x,n,sum,sum2,count,i,j;
scanf("%d",&t);
for(j=1;j<=t;j++)
{
cin>>x>>n;
sum=0;
int offer[n];
for(i=0;i<n;i++)
{
cin>>offer[i];
sum+=offer[i];
sort(offer,offer+n);
}
if(sum>=x)
{
sum2=0;
count=0;
for(i=n-1;i>=0;i--)
{
sum2+=offer[i];
if(sum2<=x)
count++;
else
break;
}
cout<<"Scenario #"<<j<<":"<<endl;
cout<<count<<endl;
cout<<endl;
}
else
{
cout<<"Scenario #"<<j<<":"<<endl;
cout<<"impossible"<<endl;
cout<<endl;
}
}
return 0;
}
The code gives the right answers for the given test cases but it causes TLE. I've tried converting my cin's and cout's to scanf/printf but, weirdly enough, the answers were not the same and I don't know how the answers were different from each other.
What's going wrong?
I suspect your main problem is here:
for(i=0;i<n;i++)
{
cin>>offer[i];
sum+=offer[i];
sort(offer,offer+n);
}
You sort the data for every number that's entered. Also, you sort random data because you only have i rows of valid data in the array, not n rows. The sort should be done once, outside the loop:
for(i=0;i<n;i++)
{
cin>>offer[i];
sum+=offer[i];
}
sort(offer,offer+n);
I used the following code for solving problem#14 but for some strange reason it gives no output.Maybe its taking too long to run???
P.S.I know that max is not supposed to be the answer but still there is no output anyways whereas for smaller values like i<100 I get the output.
#include <iostream>
long collatz(long);
int main()
{
using namespace std;
long i=3,max;
for(i=3;i<1000000;i++)
{
max=collatz(i-1);
if(collatz(i)>collatz(i-1))
{
max=collatz(i);
}
else
{
max=collatz(i-1);
}
}
cout<<max<<endl;
cin.clear();
cin.get();
}
long collatz(long n)
{
int count=0;
while(n!=1)
{
if(n%2==0)
{
n=n/2;
count+=1;
}
else
{
n=3*n+1;
}
}
return count;
}
If you call collatz with n = 113383, you get overflow and n becomes negative from which it never recovers. So you have an infinite loop as it will never be 1. You need to use a long long inside collatz.
However, your collatz functions has other problems as pointed out by others. Also, your logic for the loop in main is not correct. You are resetting max each time through the loop. So, the result you report would be either collatz(999999) or collatz(999998). But that is not be the correct answer.