POJ 2823 滑动窗口 单调队列

#include<iostream>
#include<cstdio>
using namespace std;
#define REP(r,x,y) for(register int r=(x); r<(y); r++)
#define REPE(r,x,y) for(register int r=(x); r<=(y); r++)
#ifdef sahdsg
#define DBG(...) printf(__VA_ARGS__)
#else
#define DBG(...)
#endif

#define MAXN 1000007

int arr[MAXN], que[MAXN], l, r;
int n,k;

int main() {
	#ifdef sahdsg
	freopen("in.txt", "r", stdin);
	#endif
	scanf("%d%d", &n, &k);
	REP(i,0,n) {
		scanf("%d", &arr[i]);
	}
	l=0, r=0;
	REP(i,0,k-1) {
		while(l<r && arr[que[r-1]]>arr[i]) r--;
		que[r++] = i;
	}
	bool fi = false;
	REP(i,k-1,n) {
		if(que[l]<=i-k) l++;
		while(l<r && arr[que[r-1]]>arr[i]) r--;
		que[r] = i;
		if(fi) putchar(‘ ‘); else fi = true;
		printf("%d", arr[que[l]]);
		r++;
	}
	putchar(‘\n‘);
	
	fi = false;
	l=0, r=0;
	REP(i,0,k-1) {
		while(l<r && arr[que[r-1]]<arr[i]) r--;
		que[r++] = i;
	}
	REP(i,k-1,n) {
		if(que[l]<=i-k) l++;
		while(l<r && arr[que[r-1]]<arr[i]) r--;
		que[r] = i;
		if(fi) putchar(‘ ‘); else fi = true;
		printf("%d", arr[que[l]]);
		r++;
	}
	return 0;
}