Submission #950396

#	Time	Username	Problem	Language	Result	Execution time	Memory
950396		berr	Fibonacci representations (CEOI18_fib)	C++17	50 / 100	4083 ms	2892 KiB

fib

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod =1e9+7;
 
int mul(int x, int y){
    return (x*y)%mod;
}
 
int sum(int x, int y){
    return (x+y)%mod;
}
int poww(int x, int y){
    if(y==0) return 1;
 
    int tmp =poww(x, y/2);
    tmp=mul(tmp, tmp);
 
    if(y%2) return mul(tmp, x);
    return tmp;
}
 
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
 
 
 
    int n; cin >> n;
    vector<int> a(n);
    for(auto &i: a) cin >> i;
    set<int> st;
        
    auto add =[&](int x, auto&& add)->void{
        while(st.find(x)!=st.end()){
            if(st.find(x+1)!=st.end()){
                st.erase(st.find(x+1));
                x+=2;
            }
            else if(x!=1){
                st.insert(x+1);
                st.erase(st.find(x));
 
                x=max(1LL, x-2);
            }
            else{
                st.insert(2);
                st.erase(1);
                x=0;
            }
 
        }
 
        if(x!=0) st.insert(x);
    };
 
 
    for(int i=0; i<n; i++){
        int ans=1;
        add(a[i], add);
      //  cout<<a[i]<<" ";
       
        auto it=st.end();
        it--;
 
        while(it!=st.begin()){
            int val=*it;
            if(*prev(it)+1==*it){
                st.erase(prev(it));
                st.erase(it);  
 
                add(val+1, add); 
                it=st.end(); it--;           
            }
            else{
                it--;
            }
        }
          
        
      /*  for(auto i: st) cout<<i<<" ";
            cout<<"\n";
*/
            vector<array<int, 2>> dp(st.size());
 
            dp[0]={1, (*st.begin()-1)/2};
            
            int cnt=1;
            int last=*st.begin();
            for(auto h: st){
                if(h==*st.begin()) continue;
 
                dp[cnt][0]=sum(dp[cnt-1][0], dp[cnt-1][1]);
                dp[cnt][1]=sum(mul(dp[cnt-1][0], (h-last-1)/2), mul(dp[cnt-1][1], (h-last)/2));
                cnt++; last=h;
            }
 
            cout<<sum(dp[dp.size()-1][0], dp[dp.size()-1][1])<<"\n";
        
    }
 
 
}  

Compilation message (stderr)

fib.cpp: In function 'int main()':
fib.cpp:59:13: warning: unused variable 'ans' [-Wunused-variable]
   59 |         int ans=1;
      |             ^~~

• Subtask 1: 5 / 5
• Subtask 2: 20 / 20
• Subtask 3: 15 / 15
• Subtask 4: 10 / 10
• Subtask 5: 0 / 15
• Subtask 6: 0 / 35