第一題 水仙花數
水仙花數是指一個 n 位正整數 ( n≥3 ),它的每個位上的數字的 n 次冪之和等於它本身。
例如:153 = 1 * 1 * 1 + 5 * 5 * 5 + 3 * 3 *3
求所有三位數中的水仙花數。
輸出要求:
第1個水仙花數:
...
水仙花數總和爲:
參考代碼:
public class Main {
public static void main(String[] args) {
int[] num = new int[20];
int k = 0;
for (int i = 100; i < 1000; i++) {
int a = i / 100;
int b = i % 100 / 10;
int c = i % 100 % 10;
int count = (a*a*a) + (b*b*b) + (c*c*c);
if(count == i){
num[k] = i;
k++;
}
}
int sum = 0;
for(int i = 0 ; i < k ; i ++){
System.out.println("第" + (i+1) +"個水仙花數: " + num[i]);
sum = sum + num[i];
}
System.out.println("水仙花數總和爲: " + sum);
}
}
第二題:密碼破解
題目的意思就是 輸入字符串,爲".-#"的組合,爲密碼串,將密碼串進行翻譯
"."代表1,-代表 0 , # 爲多個字符的分隔符(多個#號代表爲一個)。
將輸入的字符串轉換爲對於的字母,對於關係如下
0對應F 1對應G 2 對應R 3對應S
...(中間太多了,看switch語句中的對應關係即可)
輸入: --.####.###-..
輸出: GGS
參考代碼:
public class er {
private static char intToChar(int n){
char ch = 0;
switch(n){
case 0:
case 17:
ch = 'F';
break;
case 1:
ch = 'G';
break;
case 2:
ch = 'R';
break;
case 3:
ch = 'S';
break;
case 4:
ch = 'T';
break;
case 5:
ch = 'L';
break;
case 6:
ch = 'M';
break;
case 7:
ch = 'N';
break;
case 8:
ch = 'O';
break;
case 9:
ch = 'P';
break;
case 10:
ch = 'Q';
break;
case 11:
ch = 'W';
break;
case 12:
ch = 'X';
break;
case 13:
ch = 'Y';
break;
case 14:
ch = 'Z';
break;
case 15:
ch = 'U';
break;
case 16:
ch = 'A';
break;
case 18:
ch = 'H';
break;
case 19:
ch = 'I';
break;
case 20:
ch = 'J';
break;
case 21:
ch = 'K';
break;
case 22:
ch = 'B';
break;
case 23:
ch = 'C';
break;
case 24:
ch = 'D';
break;
case 25:
ch = 'E';
break;
case 26:
ch = 'l';
break;
case 27:
ch = 'm';
break;
case 28:
ch = 'n';
break;
case 29:
ch = 'o';
break;
case 30:
ch = 'p';
break;
case 31:
ch = 'i';
break;
case 32:
ch = 'j';
break;
case 33:
ch = 'k';
break;
case 34:
ch = 'f';
break;
case 35:
ch = 'g';
break;
case 36:
ch = 'h';
break;
case 37:
ch = 'a';
break;
case 38:
ch = 'b';
break;
case 39:
ch = 'c';
break;
case 40:
ch = 'd';
break;
case 41:
ch = 'e';
break;
case 42:
ch = 'q';
break;
case 43:
ch = 'r';
break;
case 44:
ch = 'w';
break;
case 45:
ch = 'x';
break;
case 46:
ch = 'y';
break;
case 47:
ch = 'z';
break;
case 48:
ch = 's';
break;
case 49:
ch = 't';
break;
case 50:
ch = 'u';
break;
case 51:
ch = 'v';
break;
}
return ch;
}
public static void main(String[] args) {
Scanner sin = new Scanner(System.in);
if(sin.hasNext()){
String input = sin.nextLine();
String[] point = input.split("#");
if(point.length == 0 ){
System.out.println(" ");
}
StringBuffer result = new StringBuffer();
int count = 0;
char[] res = new char[point.length];
for (int i = 0; i < point.length; i++) {
for (int j = 0; j < point[i].length(); j++) {
if(point[i].charAt(j) == '-'){
result.append('0');
}else if(point[i].charAt(j) == '.'){
result.append('1');
}
}
String num = result.toString();
count= Integer.parseInt(num,2);
if(count < 0 || count > 52){
System.out.println("ERROR");
break;
}
res[i] = intToChar(count);
result = new StringBuffer();
}
for (int i = 0; i < res.length; i++) {
System.out.print(res[i]);
}
}
}
}
第三題:查找循環調用
判斷函數之間的調用關係是否爲循環調用,例如 A調用B, B調用C, C調用A; AB爲循環調用。
A調用B,B調用A,則AB也稱爲循環調用。
輸入信息,輸入一個數字n,表示後面有n個調用關係,第二行到第n+1行爲調用關係,第n+2行爲判斷的兩個函數。
輸出信息:T(表示循環調用),F(表示不是循環調用)
輸入:3(幾個調用關係)
A B
B C
C A
A B
輸出:T
參考代碼:
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class san {
private static char isTrue(String result , String[] input){
char end = 'F';
Map<String, String> mapList = new HashMap<>();
String[] results = result.split(" ");
for (int i = 0; i < input.length; i++) {
String[] spli = input[i].split(" ");
mapList.put(spli[0], spli[1]);
}
StringBuffer su = new StringBuffer();
String in = results[0];
for (int i = 0; i < mapList.size(); i++) {
su.append(mapList.get(in));
in = mapList.get(in);
}
String res = su.toString();
if(res.contains(results[0]) && res.contains(results[1]) ){
if(res.indexOf(results[0]) > res.indexOf(results[1])){
end ='T';
}
}
return 'T';
}
public static void main(String[] args) {
Scanner sin = new Scanner(System.in);
int N = 0;
while(sin.hasNext()){
N = Integer.parseInt(sin.nextLine());
String[] input = new String[N];
for (int i = 0; i < input.length; i++) {
input[i] = sin.nextLine();
}
String result = sin.nextLine();
System.out.println(isTrue(result, input));
}
}
}