poj2823 Sliding Window（单调队列）

#include <stdio.h>
#define maxn  1010000
struct Element {
int pos, val;
}maxque[maxn], minque[maxn];
int maxhead,maxtail;
int minhead,mintail;
int n, k;
int A[maxn],B[maxn];
int main()
{
// freopen("in.txt","r",stdin);
// freopen("out.txt","w",stdout);
int i, cur, val;
while(~scanf("%d%d",&n,&k) ) {
maxhead = maxtail = 0;
minhead = mintail = 0;
cur = 0;
for (i = 0;i < k;++i) {
scanf("%d",&val);
while(maxhead < maxtail && maxque[maxtail - 1].val <= val) maxtail--;
maxque[maxtail].val = val;
maxque[maxtail].pos = i;
maxtail++;

while(minhead < mintail && minque[mintail - 1].val >= val) mintail--;
minque[mintail].val = val;
minque[mintail].pos = i;
mintail++;
}
for (i = k;i < n;++i) {
A[cur] = maxque[maxhead].val;
B[cur] = minque[minhead].val;
cur++;
scanf("%d",&val);

while(maxhead < maxtail && i - maxque[maxhead].pos >= k) maxhead++;
while(maxhead < maxtail && maxque[maxtail - 1].val <= val) maxtail--;
maxque[maxtail].val = val;
maxque[maxtail].pos = i;
maxtail++;
while(minhead < mintail && i - minque[minhead].pos >= k) minhead++;
while(minhead < mintail && minque[mintail - 1].val >= val) mintail--;
minque[mintail].val = val;
minque[mintail].pos = i;
mintail++;
}
A[cur] = maxque[maxhead].val;
B[cur] = minque[minhead].val;
cur++;
for (i = 0;i < cur;++i)
printf("%d%c", B[i], i == cur - 1?'\n':' ');
for (i = 0;i < cur;++i)
printf("%d%c", A[i], i == cur - 1?'\n':' ');
}
return 0;
}

#include <stdio.h>
#define lson(x) ((x) << 1)
#define rson(x) ((x) << 1 | 1)
#define inf 1 << 30
#define INF 0x3f3f3f3f
#define maxn 1000010
int a[maxn];
struct Node {
int Min, Max;
int l, r;
}p[maxn*4];
int mid;
int max(int x,int y) {
return x > y?x:y;
}
int min(int x,int y) {
return x < y?x:y;
}
void up(int rt) {
p[rt].Max = max(p[lson(rt)].Max, p[rson(rt)].Max);
p[rt].Min = min(p[lson(rt)].Min, p[rson(rt)].Min);
}
void build(int rt,int L,int R) {
p[rt].l = L, p[rt].r = R;
if (L == R) {
p[rt].Min = p[rt].Max = a[L];
return ;
}
//mid = (L + R) >> 1;
p[rt].Min = INF;
p[rt].Max = 0;
build(lson(rt), L, (L+R) >> 1);
build(rson(rt), ((L + R) >> 1) + 1, R);
up(rt);
}
int Max, Min;
void QueryMax(int rt,int L,int R) {
if (L <= p[rt].l && p[rt].r <= R) {
Max = max(Max, p[rt].Max);
return ;
}
// mid = (p[rt].l + p[rt].r) >> 1;
if (L <= (p[rt].l + p[rt].r) >> 1) QueryMax(lson(rt), L, R);
if (R > (p[rt].l + p[rt].r) >> 1) QueryMax(rson(rt), L, R);
}
void QueryMin(int rt,int L,int R) {
if (L <= p[rt].l && p[rt].r <= R) {
Min = min(Min, p[rt].Min);
return ;
}
//mid = (p[rt].l + p[rt].r) >> 1;
if (L <= (p[rt].l + p[rt].r) >> 1) QueryMin(lson(rt),L,R);
if (R > (p[rt].l + p[rt].r) >> 1) QueryMin(rson(rt),L,R);
}
int main()
{
// freopen("in.txt","r",stdin);
int n, k, i;
while(scanf("%d%d",&n,&k) == 2) {
for (i = 1;i <= n;++i)
scanf("%d",&a[i]);
build(1, 1, n);
for (i = k;i <= n;++i) {
Min = inf;
QueryMin(1,i - k + 1,i);
printf("%d%c",Min,i==n?'\n':' ');
}
for (i = k;i <= n;++i) {
Max = -inf;
QueryMax(1, i - k + 1,i);
printf("%d%c", Max,i == n?'\n':' ');
}
}
return 0;
}