Submission #197502

#	Time	Username	Problem	Language	Result	Execution time	Memory
197502		handlename	Xylophone (JOI18_xylophone)	C++17	100 / 100	116 ms	512 KiB

xylophone

#include "xylophone.h"
#include <bits/stdc++.h>
using namespace std;
int n,arr[5001][2];
int queries[5001][2];
void solve(int N){
    n=N;
    for (int j=0;j<2;j++){
        int temp;
        if (queries[2][0]!=0){
            temp=queries[2][0];
        }
        else {
            temp=query(1,2);
            queries[2][0]=temp;
        }
        if (j==0) arr[2][j]=arr[1][j]+temp;
        else arr[2][j]=arr[1][j]-temp;
        for (int i=3;i<=n;i++){
            int one;
            int two;
            if (queries[i][0]!=0){
                one=queries[i][0];
                two=queries[i][1];
            }
            else {
                one=query(i-1,i);
                two=query(i-2,i);
                queries[i][0]=one;
                queries[i][1]=two;
            }
            int diff=abs(arr[i-1][j]-arr[i-2][j]);
            if (arr[i-1][j]>arr[i-2][j]){
                if (one+diff==two){
                    arr[i][j]=arr[i-1][j]+one;
                }
                else arr[i][j]=arr[i-1][j]-one;
            }
            else {
                if (one+diff==two){
                    arr[i][j]=arr[i-1][j]-one;
                }
                else arr[i][j]=arr[i-1][j]+one;
            }
        }
        bool works=true;
        int mini=1e9,lpos,rpos;
        for (int i=1;i<=n;i++) mini=min(mini,arr[i][j]);
        for (int i=1;i<=n;i++){
            arr[i][j]+=(1-mini);
            if (arr[i][j]<1 || arr[i][j]>n) works=false;
            if (arr[i][j]==1) lpos=i;
            if (arr[i][j]==n) rpos=i;
        }
        if (lpos>rpos) works=false;
        if (works){
            for (int i=1;i<=n;i++) answer(i,arr[i][j]);
        }
    }
}

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:55:9: warning: 'rpos' may be used uninitialized in this function [-Wmaybe-uninitialized]
         if (lpos>rpos) works=false;
         ^~
xylophone.cpp:55:9: warning: 'lpos' may be used uninitialized in this function [-Wmaybe-uninitialized]

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