Submission #1046336

#	Time	Username	Problem	Language	Result	Execution time	Memory
1046336		dpsaveslives	Xylophone (JOI18_xylophone)	C++17	100 / 100	63 ms	848 KiB

xylophone

#include <bits/stdc++.h>
using namespace std;
int query(int, int); 
void answer(int, int);
void solve(int N){
    vector<int> diffs(N+1,0);
    for(int i = 1;i<=N-1;++i){
        diffs[i] = query(i,i+1); 
    }
    vector<int> nums(N+1,0);
    int dir = 1; nums[2] = diffs[1];
    for(int i = 1;i<=N-2;++i){
        int val = query(i,i+2);
        if(val == diffs[i]+diffs[i+1]){ //same direction
            nums[i+2] = nums[i+1]+dir*diffs[i+1];
        }
        else{
            dir = (-1)*dir;
            nums[i+2] = nums[i+1]+dir*diffs[i+1];
        }
    }
    int minn = 0, maxx = 0;
 
    for(int i = 2;i<=N;++i){
        minn = min(minn,nums[i]);
        maxx = max(maxx,nums[i]);
    }
    if(maxx+1-minn > N){
        for(int i = 2;i<=N;++i){
            nums[i] = (-1)*nums[i];
        }
        minn = 0; 
        for(int i = 2;i<=N;++i){
            minn = min(minn,nums[i]);
        }
        for(int i = 1;i<=N;++i){
            answer(i,nums[i]+1-minn);
        }
    }
    else{
        int pos1 = -1, posN = -1;
        for(int i = 1;i<=N;++i){
            if(nums[i]+1-minn == 1){
                pos1 = i;
            }
            if(nums[i]+1-minn == N){
                posN = i;
            }
        }
        if(posN < pos1){
            for(int i = 2;i<=N;++i){
                nums[i] = (-1)*nums[i];
            }
            minn = 0; 
            for(int i = 2;i<=N;++i){
                minn = min(minn,nums[i]);
            }
            for(int i = 1;i<=N;++i){
                answer(i,nums[i]+1-minn);
            }
        }
        else{
            for(int i = 1;i<=N;++i){
                nums[i] += 1-minn;
                answer(i,nums[i]);
            }
        }
    }
}

• Subtask 1: 11 / 11
• Subtask 2: 36 / 36
• Subtask 3: 53 / 53