제출 #1301439

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1301439		AksLolCoding	건물 4 (JOI20_building4)	C++17	100 / 100	162 ms	25876 KiB

building4

#include <bits/stdc++.h>
using namespace std;

const int INF = 1e9;

int n,a[1000010],b[1000010];
char ans[1000010] = {};
using Interval = pair<int,int>;
Interval dp[1000010][2];

void merge(Interval &t1,const Interval &t2,int offset){
	t1 = Interval(min(t1.first,t2.first + offset),max(t1.second,t2.second + offset));
}

signed main(){
	scanf("%d",&n);
	for(int i = 0;i < 2 * n;i++) scanf("%d",&a[i]);
	for(int i = 0;i < 2 * n;i++) scanf("%d",&b[i]);
	for(int i = 0;i < 2 * n;i++) dp[i][0] = dp[i][1] = Interval(INF,-INF);
	dp[0][0] = Interval(1,1);
	dp[0][1] = Interval(0,0);
	for(int i = 0;i < 2 * n - 1;i++){
		if(a[i] <= a[i + 1]) merge(dp[i + 1][0],dp[i][0],1);
		if(a[i] <= b[i + 1]) merge(dp[i + 1][1],dp[i][0],0);
		if(b[i] <= a[i + 1]) merge(dp[i + 1][0],dp[i][1],1);
		if(b[i] <= b[i + 1]) merge(dp[i + 1][1],dp[i][1],0);
	}
	int used = n,nxt = INF;
	for(int i = 2 * n - 1;i >= 0;i--){
		if(dp[i][0].first <= used && used <= dp[i][0].second && a[i] <= nxt){
			ans[i] = 'A';
			used--;
			nxt = a[i];
		}else if(dp[i][1].first <= used && used <= dp[i][1].second && b[i] <= nxt){
			ans[i] = 'B';
			nxt = b[i];
		}else{
			puts("-1");
			return 0;
		}
	}
	printf("%s\n",ans);
}

컴파일 시 표준 에러 (stderr) 메시지

building4.cpp: In function 'int main()':
building4.cpp:16:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |         scanf("%d",&n);
      |         ~~~~~^~~~~~~~~
building4.cpp:17:43: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         for(int i = 0;i < 2 * n;i++) scanf("%d",&a[i]);
      |                                      ~~~~~^~~~~~~~~~~~
building4.cpp:18:43: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         for(int i = 0;i < 2 * n;i++) scanf("%d",&b[i]);
      |                                      ~~~~~^~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 89 / 89