打卡第四天 P1081 [NOIP2012 提高组] 开车旅行
今天是我打卡第四天，做个省选/NOI−题吧(#^.^#)
原题链接：[NOIP2012 提高组] 开车旅行 - 洛谷
题目描述
输入格式
输出格式
输入输出样例
输入 #1
4
2 3 1 4
3
4
1 3
2 3
3 3
4 3输出 #1
1
1 1
2 0
0 0
0 0 输入 #2
10
4 5 6 1 2 3 7 8 9 10
7
10
1 7
2 7
3 7
4 7
5 7
6 7
7 7
8 7
9 7
10 7输出 #2
2
3 2
2 4
2 1
2 4
5 1
5 1
2 1
2 0
0 0
0 0说明/提示
【样例1说明】
【样例2说明】
【数据范围与约定】
C++
#include <bits/stdc++.h>
using namespace std;
const int N=1e5+100,INF=2e9;
int da[20][N][5],db[20][N][5],f[20][N][5],h[N],s[N],x[N],n,x0,m,la,lb,ansid;
double ans=INF*1.0;
struct City{
int id,h;
friend bool operator <(City a,City b){
return a.h<b.h;
}
};
multiset<City> q;
void init(){
h[0]=INF,h[n+1]=-INF;
City start;
start.id=0,start.h=INF;
q.insert(start),q.insert(start);
start.id=n+1,start.h=-INF;
q.insert(start),q.insert(start);
for(int i=n;i;i--){
City now;
now.id=i;
now.h=h[i];
q.insert(now);
auto it=q.lower_bound(now);
it--;
int lastd=(*it).id,lasth=(*it).h;
it++;
it++;
int nextd=(*it).id,nexth=(*it).h;
it--;
int ga,gb;
if(abs(nexth-h[i])>=abs(lasth-h[i]))
{
gb=lastd;
it--,it--;
if(abs(nexth-h[i])>=abs((*it).h-h[i]))
{
ga=(*it).id;
}
else
{
ga=nextd;
}
}
else {
gb=nextd;
it++,it++;
if(abs((*it).h-h[i])>=abs(lasth-h[i])){
ga=lastd;
}
else {
ga=(*it).id;
}
}
f[0][i][0]=ga,f[0][i][1]=gb;
da[0][i][0]=abs(h[i]-h[ga]);
db[0][i][1]=abs(h[i]-h[gb]);
}
}
void fun_dp()
{
for(int i=1;i<=18;i++)
for(int j=1;j<=n;j++)
for(int k=0;k<2;k++)
{
if(i==1)f[1][j][k]=f[0][f[0][j][k]][1-k],da[1][j][k]=da[0][j][k]+da[0][f[0][j][k]][1-k],db[1][j][k]=db[0][j][k]+db[0][f[0][j][k]][1-k];
else f[i][j][k]=f[i-1][f[i-1][j][k]][k],da[i][j][k]=da[i-1][j][k]+da[i-1][f[i-1][j][k]][k],db[i][j][k]=db[i-1][j][k]+db[i-1][f[i-1][j][k]][k];
}
}
void calc(int s,int x){
int p=s;
la=0,lb=0;
for(int i=18;i>=0;i--)if(f[i][p][0]&&la+lb+da[i][p][0]+db[i][p][0]<=x)la+=da[i][p][0],lb+=db[i][p][0],p=f[i][p][0];
}
void ans1(){
for(int i=1;i<=n;i++){
calc(i,x0);
double lla=(double)la/(double)lb;
if(lla<ans){
ans=lla;
ansid=i;
}
else if(lla==ans)if(h[i]>h[ansid])ansid=i;
}
cout<<ansid<<endl;
}
void ans2(){
for(int i=1;i<=m;i++){
calc(s[i],x[i]);
printf("%d %d\n",la,lb);
}
}
int main(){
cin>>n;
for(int i=1;i<=n;i++)
cin>>h[i];
cin>>x0>>m;
for(int i=1;i<=m;i++)
cin>>s[i]>>x[i];
init();
fun_dp();
ans1();
ans2();
return 0;
}Java
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StreamTokenizer;
import java.util.Arrays;
public class Main {
public static int MAXN = 100001;
public static int MAXP = 20;
public static int[] arr = new int[MAXN];
public static int[] to1 = new int[MAXN];
public static int[] dist1 = new int[MAXN];
public static int[] to2 = new int[MAXN];
public static int[] dist2 = new int[MAXN];
public static int[][] rank = new int[MAXN][2];
public static int[] last = new int[MAXN];
public static int[] next = new int[MAXN];
public static int[][] stto = new int[MAXN][MAXP + 1];
public static int[][] stab = new int[MAXN][MAXP + 1];
public static int[][] sta = new int[MAXN][MAXP + 1];
public static int[][] stb = new int[MAXN][MAXP + 1];
public static int n, m, x0;
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StreamTokenizer in = new StreamTokenizer(br);
PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
in.nextToken();
n = (int) in.nval;
for (int i = 1; i <= n; i++) {
in.nextToken();
arr[i] = (int) in.nval;
}
near();
st();
in.nextToken();
x0 = (int) in.nval;
out.println(best());
in.nextToken();
m = (int) in.nval;
for (int i = 1, s, x; i <= m; i++) {
in.nextToken();
s = (int) in.nval;
in.nextToken();
x = (int) in.nval;
travel(s, x);
out.println(a + " " + b);
}
out.flush();
out.close();
br.close();
}
public static void near() {
for (int i = 1; i <= n; i++) {
rank[i][0] = i;
rank[i][1] = arr[i];
}
Arrays.sort(rank, 1, n + 1, (a, b) -> a[1] - b[1]);
for (int i = 1; i <= n; i++) {
last[rank[i][0]] = i == 1 ? 0 : rank[i - 1][0];
next[rank[i][0]] = i == n ? 0 : rank[i + 1][0];
}
for (int i = 1; i <= n; i++) {
to1[i] = 0;
dist1[i] = 0;
to2[i] = 0;
dist2[i] = 0;
update(i, last[i]);
update(i, last[last[i]]);
update(i, next[i]);
update(i, next[next[i]]);
delete(i);
}
}
public static void update(int i, int r) {
if (r == 0) {
return;
}
int d = Math.abs(arr[i] - arr[r]);
if (to1[i] == 0 || d < dist1[i] || (d == dist1[i] && arr[r] < arr[to1[i]])) {
to2[i] = to1[i];
dist2[i] = dist1[i];
to1[i] = r;
dist1[i] = d;
} else if (to2[i] == 0 || d < dist2[i] || (d == dist2[i] && arr[r] < arr[to2[i]])) {
to2[i] = r;
dist2[i] = d;
}
}
public static void delete(int i) {
int l = last[i];
int r = next[i];
if (l != 0) {
next[l] = r;
}
if (r != 0) {
last[r] = l;
}
}
public static void st() {
for (int i = 1; i <= n; i++) {
stto[i][0] = to1[to2[i]];
stab[i][0] = dist2[i] + dist1[to2[i]];
sta[i][0] = dist2[i];
stb[i][0] = dist1[to2[i]];
}
for (int p = 1; p <= MAXP; p++) {
for (int i = 1; i <= n; i++) {
stto[i][p] = stto[stto[i][p - 1]][p - 1];
if (stto[i][p] != 0) {
stab[i][p] = stab[i][p - 1] + stab[stto[i][p - 1]][p - 1];
sta[i][p] = sta[i][p - 1] + sta[stto[i][p - 1]][p - 1];
stb[i][p] = stb[i][p - 1] + stb[stto[i][p - 1]][p - 1];
}
}
}
}
public static int best() {
int ans = 0;
double min = Double.MAX_VALUE, cur;
for (int i = 1; i < n; i++) {
travel(i, x0);
cur = (double) a / (double) b;
if (ans == 0 || cur < min || (cur == min && arr[i] > arr[ans])) {
min = cur;
ans = i;
}
}
return ans;
}
public static int a, b;
public static void travel(int s, int x) {
a = 0;
b = 0;
for (int p = MAXP; p >= 0; p--) {
if (stab[s][p] != 0 && x >= stab[s][p]) {
x -= stab[s][p];
a += sta[s][p];
b += stb[s][p];
s = stto[s][p];
}
}
if (dist2[s] <= x) {
a += dist2[s];
}
}
}Pascal
type
ar=array[1..3]of int64;
var
h,down1,down2,z,zz,l,r:array[0..100000]of longint;
f:array[1..100000,1..20]of ar;
n,m,i,j,x0,a,b:longint;
x:ar;
function edge(x,y:longint):longint;
begin
exit(abs(h[x]-h[y]));
end;
function jump(x,y:longint):ar;
var
i:longint;
begin
fillchar(jump,sizeof(jump),0);
jump[3]:=x;
for i:=20 downto 1 do
if(f[jump[3],i,3]>0)and(f[jump[3],i,1]+f[jump[3],i,2]+jump[1]+jump[2]<=y)then
begin
inc(jump[1],f[jump[3],i,1]);
inc(jump[2],f[jump[3],i,2]);
jump[3]:=f[jump[3],i,3];
end;
if f[jump[3],1,1]+jump[1]+jump[2]<=y then
begin
inc(jump[1],f[jump[3],1,1]);
jump[3]:=down2[jump[3]];
end;
end;
procedure kp(l,r:longint);
var
i,j,k,t:longint;
begin
i:=l;
j:=r;
k:=h[z[(l+r)div 2]];
repeat
while h[z[i]]<k do
inc(i);
while h[z[j]]>k do
dec(j);
if i<=j then
begin
t:=z[i];
z[i]:=z[j];
z[j]:=t;
inc(i);
dec(j);
end;
until i>j;
if i<r then
kp(i,r);
if j>l then
kp(l,j);
end;
procedure build(x:longint);
var
ll,rr:longint;
begin
ll:=x;
rr:=x;
while(ll>0)and(ll<=x)do
ll:=l[ll];
while(rr<n)and(rr<=x)do
rr:=r[rr];
if ll=0 then
down1[x]:=rr
else
if rr>n then
down1[x]:=ll
else
if edge(x,ll)<=edge(x,rr) then
down1[x]:=ll
else
down1[x]:=rr;
r[ll]:=rr;l[rr]:=ll;
if(down1[x]=ll)and(ll>0)then
begin
ll:=l[ll];
while(ll>0)and(ll<=x)do
ll:=l[ll];
end
else
if rr<=n then
begin
rr:=r[rr];
while(rr<n)and(rr<=x)do
rr:=r[rr];
end;
if ll=0 then down2[x]:=rr
else
if rr>n then
down2[x]:=ll
else
if edge(x,ll)<=edge(x,rr) then
down2[x]:=ll
else
down2[x]:=rr;
if(down1[x]<1)or(down1[x]>n)then
down1[x]:=0;
if(down2[x]<1)or(down2[x]>n)then
down2[x]:=0;
end;
begin
readln(n);
for i:=1 to n do
read(h[i]);
readln;
for i:=0 to n+1 do
z[i]:=i;
kp(1,n);
for i:=1 to n do
begin
l[z[i]]:=z[i-1];
r[z[i]]:=z[i+1];
end;
for i:=1 to n do
build(i);
for i:=1 to n do
if down2[i]>0 then
begin
f[i,1,1]:=edge(i,down2[i]);
f[i,1,3]:=down2[i];
if down1[down2[i]]>0 then
begin
f[i,1,2]:=edge(down2[i],down1[down2[i]]);
f[i,1,3]:=down1[down2[i]];
end;
end;
for j:=2 to 20 do
for i:=1 to n do
if(f[i,j-1,3]>0)and(f[f[i,j-1,3],j-1,3]>0)then
begin
f[i,j,1]:=f[i,j-1,1]+f[f[i,j-1,3],j-1,1];
f[i,j,2]:=f[i,j-1,2]+f[f[i,j-1,3],j-1,2];
f[i,j,3]:=f[f[i,j-1,3],j-1,3];
end;
readln(x0);
a:=0;
b:=0;
j:=0;
for i:=1 to n do
begin
x:=jump(i,x0);
if(a=0)and(b=0)then
begin
j:=i;
a:=x[1];
b:=x[2];
end
else
if(b=0)and(x[2]=0)and(h[i]>h[j])then
begin
j:=i;
a:=x[1];
b:=x[2];
end
else
if(x[2]<>0)and((b=0)or(x[1]/x[2]<a/b))then
begin
j:=i;
a:=x[1];
b:=x[2];
end;
end;
writeln(j);
readln(m);
for i:=1 to m do
begin
readln(a,b);
x:=jump(a,b);
writeln(x[1],' ',x[2]);
end;
end.
下一期要我讲什么题？
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