Submission #204506

#	Time	Username	Problem	Language	Result	Execution time	Memory
204506		arnold518	Abduction 2 (JOI17_abduction2)	C++14	100 / 100	1468 ms	142408 KiB

abduction2

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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 5e4;

int N, M, Q;
int A[MAXN+10], B[MAXN+10];

int LA[MAXN+10][20], RA[MAXN+10][20];
int LB[MAXN+10][20], RB[MAXN+10][20];

map<pair<pii, int>, ll> memo;

ll solve(int y, int x, int d)
{
	if(memo.find({{y, x}, d})!=memo.end()) return memo[{{y, x}, d}];
	int i, j;

	ll ret=0;
	int l, r, k;
	if(d==0)
	{
		l=y-1; r=y+1; k=B[x];
		for(i=16; i>=0; i--) if(LA[l][i]<=k) l=max(0, l-(1<<i));
		for(i=16; i>=0; i--) if(RA[r][i]<=k) r=min(N+1, r+(1<<i));

		if(l==0) ret=max(ret, (ll)y-1);
		else ret=max(ret, y-l+solve(l, x, 1));

		if(r==N+1) ret=max(ret, (ll)N-y);
		else ret=max(ret, r-y+solve(r, x, 1));
	}
	else
	{
		l=x-1; r=x+1; k=A[y];
		for(i=16; i>=0; i--) if(LB[l][i]<=k) l=max(0, l-(1<<i));
		for(i=16; i>=0; i--) if(RB[r][i]<=k) r=min(M+1, r+(1<<i));

		if(l==0) ret=max(ret, (ll)x-1);
		else ret=max(ret, x-l+solve(y, l, 0));

		if(r==M+1) ret=max(ret, (ll)M-x);
		else ret=max(ret, r-x+solve(y, r, 0));	
	}
	memo[{{y, x}, d}]=ret;
	return ret;
}

int main()
{
	int i, j;

	scanf("%d%d%d", &N, &M, &Q);
	for(i=1; i<=N; i++) scanf("%d", &A[i]);
	for(i=1; i<=M; i++) scanf("%d", &B[i]);

	for(i=1; i<=N; i++) LA[i][0]=RA[i][0]=A[i];
	for(i=1; i<=16; i++) for(j=1; j<=N; j++) LA[j][i]=max(LA[j][i-1], LA[max(0, j-(1<<(i-1)))][i-1]);
	for(i=1; i<=16; i++) for(j=1; j<=N; j++) RA[j][i]=max(RA[j][i-1], RA[min(N+1, j+(1<<(i-1)))][i-1]);

	for(i=1; i<=M; i++) LB[i][0]=RB[i][0]=B[i];
	for(i=1; i<=16; i++) for(j=1; j<=M; j++) LB[j][i]=max(LB[j][i-1], LB[max(0, j-(1<<(i-1)))][i-1]);
	for(i=1; i<=16; i++) for(j=1; j<=M; j++) RB[j][i]=max(RB[j][i-1], RB[min(M+1, j+(1<<(i-1)))][i-1]);	

	while(Q--)
	{
		int y, x;
		scanf("%d%d", &y, &x);
		printf("%lld\n", max(solve(y, x, 0), solve(y, x, 1)));
	}
}

Compilation message (stderr)

abduction2.cpp: In function 'll solve(int, int, int)':
abduction2.cpp:21:9: warning: unused variable 'j' [-Wunused-variable]
  int i, j;
         ^
abduction2.cpp: In function 'int main()':
abduction2.cpp:57:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d", &N, &M, &Q);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
abduction2.cpp:58:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1; i<=N; i++) scanf("%d", &A[i]);
                      ~~~~~^~~~~~~~~~~~~
abduction2.cpp:59:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1; i<=M; i++) scanf("%d", &B[i]);
                      ~~~~~^~~~~~~~~~~~~
abduction2.cpp:72:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &y, &x);
   ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 10 / 10
• Subtask 3: 17 / 17
• Subtask 4: 4 / 4
• Subtask 5: 56 / 56