10954 - Add All

[brianfry713]

Use a priority_queue.

[WS Ayan]

i am getting time limit in 10954 . I have tried it with priority queue and vector both. Some suggestions are badly needed. Here are the codes:
Using Priority Queue:

Code: Select all

#include<iostream>
#include<cstdio>
#include<stack>
#include<queue>
using namespace std;
int main()
{
    long long i,n,x,y,sum1,sum2;
    while(cin>>n && n)
    {
        priority_queue<long long>q;
        stack<long long>s;
        while(n--)
        {
            cin>>x;
            q.push(x);
        }
        sum1=0;
        sum2=0;
        while(q.size()!=1)
        {
            if(q.size()>2)
            {
                s.push(q.top());
                q.pop();
            }
            else
            {
                x=q.top();
                q.pop();
                y=q.top();
                q.pop();
                sum1=x+y;
                sum2=sum2+sum1;
                q.push(sum1);
                while(!s.empty())
                {
                    q.push(s.top());
                    s.pop();
                }
            }
        }
        cout<<sum2<<endl;
        /*FILE* fp;
        fp=fopen("G:\\g_output10954.txt","w");
        fprintf(fp,"%lld\n",sum2);*/

    }
return 0;
}

Using Stack:

Code: Select all

#include<iostream>
#include<cstdio>
#include<stack>
#include<queue>
#include<vector>
#include<algorithm>
using namespace std;
int main()
{
    long long i,n,x,y,sum1,sum2;
    while(cin>>n && n)
    {
        vector<long long>v;
		while(n--)
        {
            cin>>x;
            v.push_back(x);
        }
        sum1=0;
        sum2=0;
        while(v.size()!=1)
        {
           sort(v.begin(),v.end());
		   x=v[0];
			v.erase(v.begin()+0);
			if(!v.empty())
			{
				y=v[0];
				v.erase(v.begin()+0);
			}
			else
				y=0;
			
			sum1=x+y;
            sum2=sum2+sum1;
            v.push_back(sum1);
          }
        cout<<sum2<<endl;
       

    }
return 0;
}

[brianfry713]

Use just a priority_queue, you don't need a stack.

[Kaiser]

I just use a vector and at first got TLE. then i optimize the code and get AC. But it took 2.8 sec.Probably the worst runtime.

[uDebug]

brianfry713,

Thanks for all your thoughts on this thread. It really helped me out a bunch.

[sampad74]

I am getting WA.I tested my output,but did not find any mistake.Please,anybody help me.Thanks in advance.Here is my code...

Code: Select all

got ac

[lbv]

I am getting WA.I tested my output,but did not find any mistake.Please,anybody help me.Thanks in advance.Here is my code...

I'd suggest you avoid using the "long" type in C/C++, since it behaves differently in different systems. In 32-bit systems it typically has 4-bytes, and in 64-bit systems it has 8. Consider if a 4-byte integer suffices to hold every possible answer for this problem.

Also, be careful with array overflows/underflows. Consider, for example, what happens when n=2 and this piece of code is executed:

Code: Select all

            for (i = 2; i < n; i++)
                a [i - 2] = a [i];
            i = n - 3;
            while (a [i] > key)   // ....

[sampad74]

lbv wrote--
Also, be careful with array overflows/underflows. Consider, for example, what happens when n=2 and this piece of code is executed:

for (i = 2; i < n; i++)
a = a ;
i = n - 3;
while (a > key) // ....

i changed my code..

Code: Select all

my code gives me right output for n=2.
I changed long to long long int ,but got WA again.

[lbv]

i changed my code.. (..)
but got WA again.

Please post the full, latest version of your code. For people wanting to help you, combining code from different posts to keep track of the changes is not exactly fun .

[sampad74]

sorry...Here is my code.Thanks..

Code: Select all

got ac

[lighted]

You must check your program for input in this thread. It fails on this one

OK, Noboby is giving me some I/O that i wanted in another mail.

Now, would you just plz run my code, and say where I'm wrong!!!

Not working for this one:

Code: Select all

8
40952 13521 6223 42589 93489 22376 78730 38792
0

My AC's output:

Code: Select all

899661

Change line

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while (a [i] > key) {

It must be

Code: Select all

while (i > 0  &&  a[i] > key) {

Don't forget to remove your code after getting accepted.

[sampad74]

My code gave right answer for the following test case before changing previous code at my computer ..i don't know why ...

8
40952 13521 6223 42589 93489 22376 78730 38792
0

My AC's output:
899661

Afterall,got AC.Thank you.

[bgcsaif]

It gives exact output for sample input and some other critical inputs. I don't know why this code gets WA. . . .

Code: Select all

#include <stdio.h>
int main()
{
    long long int n,sum,cost,i,a[99999],j,b;
    while(scanf("%lld",&n)==1&&n!=0)
    {
        for(i=1;i<=n;i++)
            scanf("%lld",&a[i]);

        for(i=1;i<=n-1;i++)
        {
            for(j=1;j<=n-i;j++)
            {
                if(a[j]>a[j+1])
                {
                    b=a[j];
                    a[j]=a[j+1];
                    a[j+1]=b;
                }
            }
        }

        sum=a[1],cost=0;
        for(i=2;i<=n;i++)
        {
            sum=sum+a[i];
            cost=cost+sum;
        }
        if(n==1)
        cost=sum;
        printf("%lld\n",cost);
    }
    return 0;
}

[brianfry713]

Input:

Code: Select all

6
9 9 9 9 9 9
0

Correct output 144

[bgcsaif]

Please help me with sample input analysis:
For the 2nd sample input-

4
1 2 3 4
1+2=3, cost=3
3+3=6, cost=6
6+4=10, cost=10
Total= 19

So, for your input-

6
9 9 9 9 9 9
9 + 9=18, cost=18
18+9=27, cost=27
27+9=36, cost=36
36+9=45, cost=45
45+9=54, cost=54
Total=180

Shouldn't it be like that? How that can be 144?