蓝桥杯题库 历届试题部分（C++、Java）代码实现（46-60）
文章目录
- 五、历届试题
- PREV-46 填字母游戏
- PREV-47 区间移位
- PREV-48 数组操作
- PREV-49 发现环
- PREV-50 对局匹配
- PREV-51 观光铁路
- PREV-52 小数第n位
- PREV-53 分考场
- PREV-54 合根植物
- PREV-55 小计算器
将定期更新蓝桥杯习题集的解题报告~
五、历届试题
PREV-46 填字母游戏
#include import java.io.*;
import java.util.*;
public class Main {
static int dfs(char s[],int cur){
if(cur==0)return 0;
boolean ping=false;
for(int i=0;i<s.length;i++)if(s[i]=='*') {
boolean a= i-1>=0&&i-2>=0&&s[i-1]=='O'&&s[i-2]=='*';
boolean b= i+1<s.length&&i+2<s.length&&s[i+1]=='O'&&s[i+2]=='*';
boolean c= i-1>=0&&i-2>=0&&s[i-1]=='*'&&s[i-2]=='L';
boolean d= i+1<s.length&&i+2<s.length&&s[i+1]=='*'&&s[i+2]=='L';
if(!(a||b||c||d)){
s[i]='L';
int now=dfs(s,cur-1);
if(now<0) {s[i]='*';return 1;}
else if(now==0)ping=true;
s[i]='*';
}
a=i-1>=0&&i+1<s.length&&s[i-1]=='*'&&s[i+1]=='L';
b=i-1>=0&&i+1<s.length&&s[i-1]=='L'&&s[i+1]=='*';
if(!(a||b)&&!ping) {
s[i]='O';
int now=dfs(s,cur-1);
if(now<0) {s[i]='*';return 1;}
else if(now==0)ping=true;
s[i]='*';
}
}
return ping?0:-1;
}
public static void main(String[] args) throws IOException {
int T=IN.RI();
while(T-->0){
char[] s=IN.next().toCharArray();
int cnt=0;
for(char c:s)if(c=='*')cnt++;
System.out.println(dfs(s,cnt));
}
}
}
class IN {
static BufferedReader bf = new BufferedReader(new InputStreamReader(
System.in));
static StringTokenizer st = new StringTokenizer("");
public static String next() throws IOException {
while (!st.hasMoreTokens())
st = new StringTokenizer(bf.readLine());
return st.nextToken();
}
public static int RI() throws IOException {
return Integer.parseInt(next());
}
}
PREV-47 区间移位
import java.io.*;
import java.util.*;
class S implements Comparable<S>
{
int l;
int r;
public S(int l,int r) {
this.l=l;
this.r=r;
}
@Override
public int compareTo(S o) {
// TODO Auto-generated method stub
if(this.r!=o.r)
return (int) (this.r-o.r);
else {
return (int) (this.l-o.l);
}
}
}
public class Main {
static int N=20000;
static S[]s=new S[10100];
static int []vis=new int [10100];
static int n;
public static void main(String[] args) throws IOException {
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
int now =0;
String str=br.readLine();
for(int i=0;i<str.length();i++) {
now=now*10+(int)(str.charAt(i)-'0');
}
n=now;
int sum=0;
for(int i=0;i<n;i++) {
now=0;
str=br.readLine();
int a = 0,b;
for(int j=0;j<str.length();j++) {
if(str.charAt(j)==' ') {
a=now;
now=0;
}
else {
now=now*10+(int)(str.charAt(j)-'0');
}
}
b=now;
sum+=b-a;
s[i]=new S(a*2,b*2);
}
Arrays.sort(s,0,n);
int l=0,r=N;
while(l<=r) {
int mid=(l+r)/2;
//System.out.println(mid);
if(check(mid)==true) {
r=mid-1;
}
else {
l=mid+1;
}
}
if(l%2==0) {
System.out.println(l/2);
}
else
System.out.println(((double)(l)*1.0)/2.0);
}
static boolean check(int x) {
int now=0;
for(int i=0;i<10100;i++) {
vis[i]=0;
}
while(true)
{
int flag=0;
int l=0,r=n;
while(l<=r) {
int mid=(l+r)/2;
if(s[mid].r+x>=now) {
r=mid-1;
}
else l=mid+1;
}
for(int i=l;i<n;i++) {
if(s[i].l<=x+now&&vis[i]==0) {
flag=1;
vis[i]=1;
if(now<=s[i].l+x) now+=s[i].r-s[i].l;
else now =s[i].r+x;
break;
}
}
if(now>=20000) return true;
if(flag==0) return false;
}
}
}
PREV-48 数组操作
import java.util.*;
public class Main {
public static int n,m,ca;
public static int[] arr;
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
ca=in.nextInt();
n=in.nextInt();
m=in.nextInt();
arr=new int[n];
for(int i=0;i<n;i++){
arr[i]=in.nextInt();
}
while(m>0){
m--;
int t=in.nextInt();
int l,r,d;
switch (t){
case 1:
l=in.nextInt();
r=in.nextInt();
d=in.nextInt();
for(int i=l-1;i<r;i++){
arr[i]+=d;
}
break;
case 2:
l=in.nextInt()-1;
r=in.nextInt()-1;
int l0=in.nextInt()-1;
int r0=in.nextInt()-1;
System.arraycopy(arr,l0,arr,l,r-l+1);
break;
case 3:
long sum=0;
l=in.nextInt()-1;
r=in.nextInt();
for(int i=l;i<r;i++){
sum+=arr[i];
}
System.out.println(sum);
break;
}
}
}
}
PREV-49 发现环
简记：两次dfs找环即可，基环树。
#include
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;
import java.util.Vector;
public class Main {
static int N=100010;
static int []cnt=new int [N];
static ArrayList []l = new ArrayList[N];
static int []vis=new int [N];
static int []q=new int [N];
static int num=0;
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
for(int i=0;i<N;i++) {
l[i]=new ArrayList();
}
String str=br.readLine();
int now =0,n;
for(int i=0;i<str.length();i++) {
now=now*10+(int)(str.charAt(i)-'0');
}
n=now;
for(int i=0;i<n;i++) {
str=br.readLine();
int a = 0,b;
now=0;
for(int j=0;j<str.length();j++) {
if(str.charAt(j)==' ') {
a=now;
now=0;
}
else {
now=now*10+(int)(str.charAt(j)-'0');
}
}
b=now;
cnt[a]++;
cnt[b]++;
l[a].add(b);
l[b].add(a);
}
for(int i=1;i<=n;i++) {
if(cnt[i]==1) {
q[num++]=i;
}
}
int pre=0;
while(num!=pre) {
int i=pre;
pre=num;
for(;i<num;i++) {
int aa=q[i];
if(cnt[aa]==1) {
vis[aa]=1;
cnt[aa]--;
for(int j=0;j<l[aa].size();j++) {
cnt[(int) l[aa].get(j)]--;
if(cnt[(int) l[aa].get(j)]==1) {
q[num++]=(int) l[aa].get(j);
}
}
}
}
}
int pp=0;
for(int i=1;i<=n;i++) {
if(vis[i]==0) {
if(pp==0) {
System.out.print(i);
pp=1;
}
else {
System.out.print(" "+i);
}
}
}
System.out.println();
}
}
PREV-50 对局匹配
//#define LOCAL
#include
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StreamTokenizer;
public class Main {
public static int[] cnt = new int[100005];
private static int k;
public static void main(String[] args) throws IOException {
StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
in.nextToken();
int n = (int)in.nval;
in.nextToken();
k = (int)in.nval;
int maxx = 0;
for (int i = 0; i < n; i++) {
in.nextToken();
int d = (int)in.nval;
cnt [d]++;
maxx = Math.max(maxx, d);
}
int ans = 0;
for (int i = 0; i + k <= maxx; i++) {
while (cnt[i] > 0 && cnt[i + k] > 0 && k !=0) {
ans++;
cnt[i]--;
cnt[i + k]--;
}
if (cnt[i] >= 2 && k == 0) {
ans += cnt[i]-1;
cnt[i] = 1;
}
}
out.println(n - ans);
out.flush();
}
}
PREV-51 观光铁路
对不起我承认这道题写的就是垃圾
#include PREV-52 小数第n位
#include import java.util.*;
import java.io.*;
public class Main{
static List<Integer> num = new ArrayList<Integer>();
public static void main(String[] args) throws IOException{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String data[] = br.readLine().split(" ");
int a = Integer.parseInt(data[0]);
int b = Integer.parseInt(data[1]);
int n = Integer.parseInt(data[2]);
a = a % b;
int len = cal(a, b); //去掉循环节的长度
for(int i = n - 1; i <= n + 1; i++){
if(i < len) System.out.print(num.get(i));
else
System.out.print(num.get((i - len) % (num.size() - len) + len));
}
}
private static int cal(int a, int b){
HashMap<Integer, Integer> map = new HashMap<Integer, Integer>(); //使用哈希表存储每次出现的值和长度
while(true){
map.put(a, num.size());
a *= 10;
num.add(a / b);
if(map.containsKey(a % b))
return map.get(a % b);
a %= b;
}
}
}
PREV-53 分考场
#include import java.io.*;
public class Main{
static int[][] map;
static int[][] color;
static int min;
static int n;
public static void main(String[] args) throws IOException{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
n = Integer.parseInt(br.readLine());
int m = Integer.parseInt(br.readLine());
map = new int[n + 1][n + 1];
color = new int[n + 1][n + 1];
for(int i = 0; i < m; i++){
String data[] = br.readLine().split(" ");
int v = Integer.parseInt(data[0]);
int u = Integer.parseInt(data[1]);
map[v][u] = map[u][v] = 1;
}
min = n;
dfs(1, 0);
System.out.print(min);
}
private static void dfs(int x, int room){
if(room >= min) return;
if(x > n){
if(room < min) min = room;
return;
}
for(int i = 1; i <= room; i++){
int k = 0;
while(color[i][k] != 0 && map[x][color[i][k]] == 0)
k++;
if(color[i][k] == 0){
color[i][k] = x;
dfs(x + 1, room);
color[i][k] = 0;
}
}
color[room + 1][0] = x;
dfs(x + 1, room + 1);
color[room + 1][0] = 0;
}
}
PREV-54 合根植物
#include
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.HashSet;
import java.util.Set;
public class Main {
public static int[] head;
public static void main(String[] args) throws IOException {
StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
in.nextToken();
int m = (int)in.nval;
in.nextToken();
int n = (int)in.nval;
in.nextToken();
int k = (int)in.nval;
head = new int[m*n];
for (int i = 0; i < m*n; i++) {
head[i] = i;
}
for (int i = 0; i < k; i++) {
in.nextToken();
int a = (int)in.nval-1;
in.nextToken();
int b = (int)in.nval-1;
u(a,b);
}
Set<Integer> set = new HashSet<Integer>();
for (int i = 0; i < m*n; i++) {
set.add(f(i));
}
out.println(set.size());
out.flush();
}
private static int f(int i) {
if (head[i] == i) {
return i;
}
return head[i] = f(head[i]);
}
private static void u(int a, int b) {
if (f(a) == f(b)) {
return;
}
head[f(a)] = f(b);
}
}
PREV-55 小计算器
#include
if (n)
if (zh == 1)
res = base = base + b;
else if (zh == 2)
res = base = base - b;
else if (zh == 3)
res = base = base * b;
else if (zh == 4)
res = base = base / b;
else if (zh == 5)
res = base = base % b;
}
void equ(ll r) {
if (r == 0) return;
equ(r / jz);
int x = r % jz;
// cout<
if (x < 10)
putchar(x + '0');
else
putchar(x - 10 + 'A');
}
int main() {
// ios::sync_with_stdio(false);
int t;
cin >> t;
getchar();
while (t--) {
gets(chs);
if (chs[0] == 'C') {
if (chs[1] == 'L')
m = n = 0;
else {
if (!isdigit(chs[8]))
jz = chs[7] - '0';
else
jz = (chs[7] - '0') * 10 + chs[8] - '0';
}
} else if (chs[0] == 'N')
num();
else if (chs[0] == 'A')
zh = 1;
else if (chs[0] == 'S')
zh = 2;
else if (chs[0] == 'M') {
if (chs[1] == 'U')
zh = 3;
else
zh = 5;
} else if (chs[0] == 'D')
zh = 4;
else if (chs[0] == 'E') {
// cout<
if (res)
equ(res);
else
putchar('0');
putchar('\n');
}
}
}
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Main {
public static void main(String[] args) throws IOException {
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
int n = Integer.parseInt(in.readLine());
long sum = 0;
int jinzhi = 10;
String yunsuan = "ADD";
for (int i = 0; i < n; i++) {
String s = in.readLine();
if (s.equals("CLEAR")) {
yunsuan = "ADD";
sum = 0;
} else if (s.contains("NUM")) {
long t = Long.parseLong(s.substring(s.indexOf(" ") + 1), jinzhi);
if (yunsuan.equals("ADD")) {
sum += t;
} else if (yunsuan.equals("SUB")) {
sum -= t;
} else if (yunsuan.equals("MUL")) {
sum *= t;
} else if (yunsuan.equals("DIV")) {
sum /= t;
} else if (yunsuan.equals("MOD")) {
sum %= t;
}
} else if (s.contains("CHANGE")) {
jinzhi = Integer.parseInt(s.substring(s.indexOf(" ") + 1));
} else if (s.equals("EQUAL")) {
System.out.println(Long.toString(sum, jinzhi).toUpperCase());
} else if (s.equals("ADD")) {
yunsuan = "ADD";
} else if (s.equals("SUB")) {
yunsuan = "SUB";
} else if (s.equals("MUL")) {
yunsuan = "MUL";
} else if (s.equals("DIV")) {
yunsuan = "DIV";
} else if (s.equals("MOD")) {
yunsuan = "MOD";
}
}
}
}