#include<iostream>
#include<algorithm>
#define INT unsigned __int128
using namespace std;
INT base[25][25],lit[25],n,error=0;
void expbase(INT p,INT q)
{
for(INT i=1;i<=n;i++)
{
base[p][i]=1;
base[i][q]=1;
}
INT cp=p,cq=q;
while(cp>=1&&cp<=n&&cq>=1&&cq<=n)
{
base[cp][cq]=1;
cp--;
cq++;
}
cp=p,cq=q;
while(cp>=1&&cp<=n&&cq>=1&&cq<=n)
{
base[cp][cq]=1;
cp++;
cq--;
}
cp=p,cq=q;
while(cp>=1&&cp<=n&&cq>=1&&cq<=n)
{
base[cp][cq]=1;
cp--;
cq--;
}
cp=p,cq=q;
while(cp>=1&&cp<=n&&cq>=1&&cq<=n)
{
base[cp][cq]=1;
cp++;
cq++;
}
base[p][q]=2;
return;
}
void make(INT ed)
{
INT d[25][25]={0,},ch=0,mult=1;
for(INT i=1;i<=n;i++)
{
INT cop[25][25]={0,},co=0;
if(lit[i])continue;
for(INT p=1;p<=n;p++)
{
for(INT q=1;q<=n;q++)
{
cop[p][q]=d[p][q];
d[p][q]=0;
}
}
if(i==ed)
{
/*Insert Queen*/
for(INT j=1;j<=n;j++)
{
if(cop[i][j]!=(1<<mult)-1&&!base[i][j]){expbase(i,j);return;}
else if(j==n){error=1;return;}
}
}
else
{
/*Check the possibility*/
for(INT j=1;j<=n;j++)
{
if(!base[i][j])
{
INT ch[25][25]={0,};
for(INT p=1;p<=n;p++)
for(INT q=1;q<=n;q++)
d[p][q]=(d[p][q]<<mult);
for(INT p=1;p<=n;p++)if(!ch[i][p]){d[i][p]+=(1<<mult)-1;ch[i][p]=1;}
for(INT p=1;p<=n;p++)if(!ch[p][j]){d[p][j]+=(1<<mult)-1;ch[p][j]=1;}
INT ci=i,cj=j;
while(ci>=1&&ci<=n&&cj>=1&&cj<=n)
{
if(!ch[ci][cj]){d[ci][cj]+=(1<<mult)-1;ch[ci][cj]=1;}
ci--;cj++;
}
ci=i,cj=j;
while(ci>=1&&ci<=n&&cj>=1&&cj<=n)
{
if(!ch[ci][cj]){d[ci][cj]+=(1<<mult)-1;ch[ci][cj]=1;}
ci++;cj++;
}
ci=i,cj=j;
while(ci>=1&&ci<=n&&cj>=1&&cj<=n)
{
if(!ch[ci][cj]){d[ci][cj]+=(1<<mult)-1;ch[ci][cj]=1;}
ci++;cj--;
}
ci=i,cj=j;
while(ci>=1&&ci<=n&&cj>=1&&cj<=n)
{
if(!ch[ci][cj]){d[ci][cj]+=(1<<mult)-1;ch[ci][cj]=1;}
ci--;cj--;
}
for(INT p=1;p<=n;p++)
for(INT q=1;q<=n;q++)
if(!ch[p][q])d[p][q]+=(cop[p][q]|cop[i][j]);
co++;
}
}
mult*=co;
}
}
return;
}
int main()
{
scanf("%lld",&n);
for(INT i=1;i<=n;i++)
{
for(INT j=1;j<=n;j++)
{
scanf("%lld",&base[i][j]);
if(base[i][j]==2)lit[i]=1;
}
}
cout<<endl;
for(INT i=n;i>=1;i--)
{
if(!lit[i])make(i);
if(error){cout<<"does not exist"<<endl;return 0;}
}
for(INT i=1;i<=n;i++)
for(INT j=1;j<=n;j++)
if(base[i][j]==0)base[i][j]=2;
cout<<endl;
for(INT i=1;i<=n;i++)
{
for(INT j=1;j<=n;j++)
printf("%llx ", (unsigned long long)(base[i][j] & 0xFFFFFFFFFFFFFFFF));
cout<<endl;
}
return 0;
}
The above code is written to solve the n-queens problem, which is the problem presented to solve the P versus NP problem.
Currently, the above code only works if the multiplication of the number of zeros present in each column is 128 or less.
I wonder if I can solve the n-queens problem by making several modifications to this algorithm.
Related
can any body please tell me whats wrong in this code? i have already spent almost 1 day behind this to find out whats wrong in this. this heap sort code fails for some input.
i.e. for input array arr = {1,5,2,4,3,6,0,7,9,8}.
this code should print
{9,8,7,6,5,4,3,2,1,0} but this code gives {5,9,8,7,6,4,3,2,1,0}
#include<iostream>
using namespace std;
void printarr(int *arr,int n)
{
for(int i=0;i<=n;i++)
cout<<arr[i]<<" ";
cout<<endl;
}
void heapify(int *arr,int i,int n)
{
int max=i;
if(arr[max]<arr[(2*i)+1] && (2*i)+1<=n)
max=(2*i)+1;
if(arr[max]<arr[(2*i)+2] && (2*i)+2<=n)
max=(2*i)+2;
if(i!=max)
{
swap(arr[max],arr[i]);
heapify(arr,max,n);
}
}
void buildheap(int *arr,int i,int j)
{
for(;i<=(i+j)/2;i++)
heapify(arr,i,j);
}
int* heapsort(int *arr,int i,int n)
{
buildheap(arr,0,n-1);
int *b,index=0;
b=new int[n];
while(n>=i)
{
b[index++]=arr[i];
arr[i]=arr[n--];
heapify(arr,i,n);
}
return b;
}
int main()
{
int *arr,n;
cout<<"how many elements?"<<endl;
cin>>n;
cout<<"enter elements : "<<endl;
arr=new int [n];
for(int i=0;i<n;i++)
cin>>arr[i];
arr=heapsort(arr,0,n-1);
printarr(arr,n-1);
}
I found 2 errors
You should first check out of bound condition and then compare.
Change if(arr[max]<arr[(2*i)+1] && (2*i)+1<=n) max=(2*i)+1;
To if((2*i)+1<=n && arr[max]<arr[(2*i)+1])
If you are building a heap, You run loop like this. Because of what you have written in heapify
Change void buildheap(int *arr,int i,int j) { for(;i<=(i+j)/2;i++) heapify(arr,i,j); }
To void buildheap(int *arr,int i,int j) { for(i = j/2; i >= 0;i--) heapify(arr,i,j);}
Final Code
#include<iostream>
using namespace std;
void printarr(int *arr,int n)
{
for(int i=0;i<=n;i++)
cout<<arr[i]<<" ";
cout<<endl;
}
void heapify(int *arr,int i,int n)
{
int max=i;
max=(2*i)+1;
if((2*i)+2<=n && arr[max]<arr[(2*i)+2])
max=(2*i)+2;
if(i!=max)
{
swap(arr[max],arr[i]);
heapify(arr,max,n);
}
}
void buildheap(int *arr,int i,int j)
{
for(i = j/2; i >= 0;i--)
heapify(arr,i,j);
}
int* heapsort(int *arr,int i,int n)
{
buildheap(arr,0,n-1);
int *b,index=0;
b=new int[n];
while(n>=i)
{
b[index++]=arr[i];
arr[i]=arr[n--];
heapify(arr,i,n);
}
return b;
}
int main()
{
int *arr,n;
cout<<"how many elements?"<<endl;
cin>>n;
cout<<"enter elements : "<<endl;
arr=new int [n];
for(int i=0;i<n;i++)
cin>>arr[i];
arr=heapsort(arr,0,n-1);
printarr(arr,n-1);
}
The below code in c++ is to find the distance between any two nodes in a graph but there is some logical error where I tried to find but can't. Everything seems to be perfect but I can say that there is something wrong with a break inside if condition inside for loop which is inside while(s.!empty()).
#include<bits/stdc++.h>
#include<iostream>
using namespace std;
int find_distance(int link[100][100],int start,int dest,int n,int e)
{
start=start-1;
dest=dest-1;
if(start==dest)return 0;
int visited[100];
int distance;
for(int i=0;i<n;i++)
{
visited[i]=0;
}
stack<int>s;
int k;s.push(start);
visited[start]=1;
bool found=false;
int count =0;
while(!s.empty())
{
k=s.top();
int i;
int check_point=1;
for(i=0;i<n;i++)
{
if(link[k][i]==1 && visited[i]!=1)
{
s.push(i);
count ++;
check_point=0;
if(i==dest)
{
cout<<"found";
found=true;
}
break;
}
}
if(check_point==1)
{
s.pop();
count--;
}
if(found)break;
}
return count;
}
int main()
{
int n,e,a,b;
int link[100][100];
cout<<"enter the number of vertices and edges";
// cin>>n>>e;
n=5;e=4;
for(int i=0;i<n;i++)
{
for(int j=0;j<n;j++)
{
if(i==j)
link[i][j]=0;
else
link[i][j]=INT_MAX;
cout<<link[i][j]<<" ";
}
cout<<endl;
}
int input[4][2]={{1,2},{1,3},{2,4},{2,5}};
for(int i=0;i<e;i++)
{
a=input[i][0];
b=input[i][1];
link[a-1][b-1]=1;
link[b-1][a-1]=1;
}
for(int i=0;i<n;i++)
{
for(int j=0;j<n;j++)
{
cout<<link[i][j]<<" ";
}
cout<<endl;
}
while(true) {
cout<<endl<<"enter the starting point .. ";
int start;
cin>>start;
int dest;
cout<<endl<<"enter the destination point .. ";
cin>>dest;
int distance = find_distance(link,start,dest,n,e);
cout<<endl<<"distance is "<<distance;
}
return 0;
}
I am solving a problem on my college judge where i have to all lis sequences. The n is very small so, i am generating all subsets and if they are increasing and of longest length, i am printing it. What's wrong in my code? Or may be any problem with order?
#include<iostream>
#include<cmath>
#include<algorithm>
#include<sstream>
#include<vector>
#include<map>
using namespace std;
int a[100005];
int l[100005];
vector< vector<int> > V;
int main()
{
int n,r,c;
cin>>n;
for(int i=0;i<n;i++)
{
cin>>a[i];
l[i]=1;
}
for(int i=0;i<n;i++)
{
for(int j=0;j<i;j++)
{
if(a[i]>a[j]&&l[i]<l[j]+1)
{
l[i]=l[j]+1;
}
}
}
vector<int> v;
r=0;
int cnt=0;
for(int i=0;i<pow(2,n);i++)
{
for(int j=0;j<n;j++)
{
if(i & (1<<j))
{
v.push_back(a[j]);
}
}
int f=0;
if(v.size()==*max_element(l,l+n))
{
int ss=v.size();
for(int x=0;x<ss-1;x++)
{
if(v[x]>=v[x+1])
{
f=-1;
break;
}
}
if(f==0)
{
V.push_back(v);
}
}
v.clear();
}
for(int i=0;i<V.size();i++)
{
for(int j=0;j<V[i].size();j++)
{
cout<<V[i][j];
if(j!=V[i].size()-1)
cout<<" ";
}
cout<<endl;
}
return 0;
}
Given a horizontal section of wall , and N layers of paints applied from co-ordinates Xi to Yi , Output the distinct number of layers visible.
Here is the problem link http://www.spoj.com/problems/POSTERS/
Here is my solution http://ideone.com/gBJKnL
Approach :
I tried solving the problem by lazily updating child node values through a Segment Tree , the most recent value replaces the older one in their lazy updates. This way only the recent paint gets applied into the horizontal cross-section. although the code works fine on custom test cases , It takes a lot of memory and gets aborted by the Online Judge .
#include <iostream>
#include <set>
#include <vector>
#define MAX 10000000+100
typedef long long int ll;
using namespace std;
ll Tree[3*MAX],lazy[MAX*2];
void Update(ll s,ll start,ll end,ll left,ll right,ll value)
{
if(lazy[s]!=0)
{
Tree[s]=(lazy[s]*(end-start+1));
if(start!=end)lazy[2*s+1]=lazy[s],lazy[s*2+2]=lazy[s];
lazy[s]=0;
}
if(start>end||left>end||right<start)return;
if(start>=left&&end<=right)
{
Tree[s] = (value*(end-start+1));
if(start!=end)
{
lazy[2*s+1]=value;
lazy[2*s+2]=value;
}
return ;
}
ll mid=(start+end)/2;
Update(2*s+1,start,mid,left,right,value);
Update(2*s+2,mid+1,end,left,right,value);
Tree[s] = Tree[s*2+1]+Tree[2*s+2];
}
ll Read(ll s,ll start,ll end,ll left,ll right)
{
if(start>end||start>right||end<left)return 0;
if(lazy[s]!=0)
{
Tree[s]=(lazy[s]*(end-start+1));
if(start!=end)
{
lazy[2*s+1]=lazy[s];
lazy[2*s+2]=lazy[s];
}
lazy[s]=0;
}
if(start>=left&&end<=right)return Tree[s];
else return (Read(2*s+1,start,(start+end)/2,left,right)+Read(2*s+2,1+((start+end)/2),end,left,right));
}
int main() {
// your code goes here
ll t;
cin>>t;
while(t--)
{
ll n,z=1,li=-1;
cin>>n;
vector<pair<ll,ll> > b;
for(ll i=0;i<n;i++)
{
ll u,v;
li = max(li,v);
cin>>u>>v;
b.push_back(make_pair(u-1,v-1));
}
for(auto v: b)
Update(0,0,li+2,v.first,v.second,z++);
set<ll> a;
for(ll i=0;i<li+2;i++)cout<<Read(0,0,li+2,i,i)<<" ",a.insert(Read(0,0,li+2,i,i));
cout<<endl;
cout<<a.size()-1<<endl;
}
return 0;
}
Here is how you should be doing it:
#include <bits/stdc++.h>
#define mx 400005
using namespace std;
int tr[mx], lz[mx];
int t, n, l, r;
void update(int node, int s, int e, int l, int r, int val)
{
if(lz[node]!=0)
{
tr[node]=lz[node];
if(s!=e)
{
lz[node*2]=lz[node];
lz[node*2+1]=lz[node];
}
lz[node]=0;
}
if(s>e || r<s || l>e)
return;
if(s>=l && e<=r)
{
tr[node]=val;
if(s!=e)
{
lz[2*node]=val;
lz[2*node+1]=val;
}
return;
}
int m=s+(e-s)/2;
update(2*node,s,m,l,r,val);
update(2*node+1,m+1,e,l,r,val);
tr[node]=val;
//tr[node]=max(tr[2*node],tr[2*node+1]);
}
int query(int node, int s, int e, int l, int r)
{
if(r<s || e<l)
return 0;
if(lz[node]!=0)
{
tr[node]=lz[node];
if(s!=e)
{
lz[node*2]=lz[node];
lz[node*2+1]=lz[node];
}
lz[node]=0;
}
if(l<=s && r>=e)
return tr[node];
int m=s+(e-s)/2;
return query(2*node,s,m,l,r)+query(2*node+1,m+1,e,l,r);
}
int main()
{
//cout << "Hello world!" << endl;
cin>>t;
while(t--)
{
for(int i=0; i<mx; i++) tr[i]=0;
cin>>n;
int lr[n+1][2];
map<int,bool> mark;
vector<int> vec;
//int c=0;
for(int i=0; i<n; i++)
{
cin>>l>>r;
lr[i][0]=l;
lr[i][1]=r;
if(mark[l]==0)
{
vec.push_back(l);
mark[l]=1;
}
if(mark[r]==0)
{
vec.push_back(r);
mark[r]=1;
}
}
sort(vec.begin(), vec.end());
map<int,int> mp;
int c=1;
for(int i=0; i<vec.size(); i++)
mp[vec[i]]=c++;
for(int i=0; i<n; i++)
{
//cout<<mp[lr[i][0]]<<" "<<mp[lr[i][1]]<<"\n";
update(1,1,vec.size(),mp[lr[i][0]],mp[lr[i][1]],i+1);
}
set<int> ans;
for(int i=1; i<=vec.size(); i++)
{
//cout<<query(1,1,vec.size(),i,i)<<" ";
ans.insert(query(1,1,vec.size(),i,i));
}
int k = ans.size();
if(ans.find(0) != ans.end())
k--;
printf("%d\n",k);
}
return 0;
}
It says vector subscript out of range when achieving if statement. I think I added extra int to floor, or extra floor vector to 2D vector. I am using VS 2010(C++)
I tried to find it on other questions but not succeeded.
bool is_perfect_square(int);
int main()
{
int cust;
vector<int>floor;
vector<vector<int>>hotel;
floor.push_back(0);
hotel.push_back(floor);
hotel[0][0]=1;
for(cust=2; ; cust++)
{
for(int i=0; i<=hotel.size(); i++)
{
if(is_perfect_square(cust+hotel[i][floor.size()]))
{
floor.push_back(0);
hotel[i][cust]=cust;
break;
}
else
{
hotel.push_back(floor);
hotel[hotel.size()][0]=cust;
}
}
}
int sum=0;
for(int a=1; a<=hotel.size(); a++)
{
for(int b=1; b<=floor.size(); b++)
{
if(pow(a-1,2)+pow(b-1,2)==14234886498625)
sum+=hotel[a-1][b-1];
}
}
cout<<sum<<endl;
system("pause");
return 0;
}
bool is_perfect_square(int n)
{
int root=floor(sqrt(n));
return n == root * root;
}
I put my answers in the comments.
bool is_perfect_square(int);
int main()
{
int cust;
vector<int>floor;
vector<vector<int>>hotel;
floor.push_back(0);
hotel.push_back(floor);
hotel[0][0]=1;
// you may not be able to get out of this loop
// because the "break" below only exits one level of the loop.
for(cust=2; ; cust++)
{
// this should be changed to "i<hotel.size()",
// because the subscript of a vector ranges from 0 to its size minus one.
for(int i=0; i<=hotel.size(); i++)
{
// here "floor.size()" should be floor.size() - 1, the same reason.
if(is_perfect_square(cust+hotel[i][floor.size()]))
{
floor.push_back(0);
hotel[i][cust]=cust;
break;
}
else
{
hotel.push_back(floor);
hotel[hotel.size()][0]=cust;
}
}
}
int sum=0;
for(int a=1; a<=hotel.size(); a++)
{
for(int b=1; b<=floor.size(); b++)
{
if(pow(a-1,2)+pow(b-1,2)==14234886498625)
sum+=hotel[a-1][b-1];
}
}
cout<<sum<<endl;
system("pause");
return 0;
}
bool is_perfect_square(int n)
{
int root=floor(sqrt(n));
return n == root * root;
}