Bài tập Java Full HD ko che
trantri2k2
java
4 years ago
4.9 kB
33
Indexable
import java.util.*; import java.util.Arrays; public class Main { // Ham public static boolean laSoNguyenTo(int n){ if(n < 2) return false; for(int i=2;i<=Math.sqrt(n);i++) { if(n % i == 0) return false; } return true; } public static int laSoFib(int n) { int f0 = 0; int f1 = 1; int fn = 1; if (n < 0) { return -1; } else if (n == 0 || n == 1) { return n; } else { for (int i = 2; i < n; i++) { f0 = f1; f1 = fn; fn = f0 + f1; } } return fn; } // Cau 8 den cau 18 public static void cau8(){ System.out.print("Nhap n:"); int n = sc.nextInt(); System.out.println(n+" so nguyen to dau tien la:"); int sum=0,count=0; for(int i=0;i<100;i++){ if(count==n) break; if(laSoNguyenTo(i)){ count++; System.out.print(i+" "); sum+=i; } } System.out.println("\nTong "+n+" so nguyen to dau tien la:"+sum); } public static void cau9(){ System.out.print("Nhap mot chuoi:"); String str = sc.nextLine(); int count=0; for(int i=0;i<str.length();i++){ if(str.charAt(i) == 'a') count++; } System.out.println("So luong chu 'a' trong chuoi la: "+count); } public static void cau10(){ System.out.print("Nhap mot chuoi:"); String str = sc.nextLine(); System.out.println("Chuoi sau khi tach la:"); int count=1; for(int i=0;i<str.length();i++){ if(str.charAt(i) == ' ') count++; } String arrStr[] = new String[count]; arrStr = str.split(" "); for(int i=0;i<count;i++){ System.out.println(arrStr[i]); } } public static void cau11(){ System.out.print("Nhap mot chuoi:"); String str = sc.nextLine(); int count=0; for(int i=0;i<str.length();i++){ if(Character.isDigit(str.charAt(i))) count+=1; } System.out.println("So ky tu la so trong chuoi la:"+count); } public static void cau12(){ int count=0,sum=0; System.out.println("Nhap mot day so xen ke bat ky:"); while(count!=10){ int n = sc.nextInt(); if(n%2==0){ System.out.print(n+" "); sum+=n; count++; } } System.out.println("\nTong cua 10 so chan dau tien la:"+sum); } public static void cau13(){ System.out.println("So le tu 1 den 99 la:"); for(int i=0;i<100;i++){ if(i%2==1) System.out.print(i+" "); } } public static void cau14(){ System.out.println("Cac so la boi so cua 7 la:"); int rs=7,i=1,sum=0; while(true){ rs = 7 * (i++); if(rs>100) break; sum+=rs; } System.out.println("\nTong cac so la boi cua 7 (1->100):"+sum); } public static void cau15(){ System.out.print("Nhap 1 day so:"); String str = sc.nextLine(); String myStr[] = str.split(" "); int max = Integer.parseInt(myStr[0]); int min = Integer.parseInt(myStr[0]); for(int i=1;i<myStr.length;i++){ int num1 = Integer.parseInt(myStr[i]); int num2 = Integer.parseInt(myStr[i]); if(num1 > max) max = num1; if(num2 < min) min = num2; } System.out.println("Min:"+min+"\nMax:"+max); } public static void cau16(){ System.out.print("Nhap mot so bat ky:"); int n = sc.nextInt(); if(n==0) System.out.println("zero"); System.out.println(n%2==0?"So chan":"So le"); } public static void cau17(){ System.out.println("Boi cua so 3 (tu 300 den 3):"); int rs=3,i=1; int a[] = new int[100]; //So luong phan tu mac dinh la 100 (tu hieu nha :)) ) while(true){ rs = 3*i; if(rs>300) break; a[i-1] = rs; i++; } for(i=a.length-1;i>=0;i--){ System.out.print(a[i]+" "); } } public static void cau18(){ System.out.print("Nhap n:"); int n = sc.nextInt(); System.out.println(n+" so fib dau tien la"); int i=1; while(i <= n){ System.out.print(laSoFib(i++)+" "); } } static Scanner sc = new Scanner(System.in); public static void main(String[] args) { //cau8(); //cau9(); //cau10(); //cau11(); //cau12(); //cau13(); //cau14(); //cau15(); //cau16(); //cau17(); //cau18(); } }
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