#include<stdio.h>
#include<iostream>
using namespace std;
#define N 10000

int n;
int ans[N], q[N];

void blockmin(int d, int *x, int *ans) {
    // d is the block size
    // x[] is an array of size n
    // the answer is returned in an array ans[] of size at least n-d+1
	
    int q1 = 0, q2 = 0;

    for (int i = 0; i < n; i++) {
	while (q1 > q2 && x[q[q1 - 1]] >= x[i]) q1--;
	q[q1++] = i;
	
	if (i >= d && q[q2] == i - d) q2++;

	if (i >= d-1) {
	    ans[i-(d-1)] = x[q[q2]];
	}
    }
}

int main() {
    int x[] = {1,2,3,4,3,2,1};
    n = 7;
    int d = 3;
    blockmin (d, x, ans);
    for (int i=0; i<n-d+1; i++) {
	printf("%d ", ans[i]);
    }
    printf("\n");
    return 0;
}