Java BASIC Programming questions

Java BASIC Programming Questions

1. Print out the case

1  Public classprog19{2      Public Static voidMain (string[] args) {3         intn = 5;4 Printstar (n);5         }6     7     //Print stars8     Private Static voidPrintstar (intN) {9         //print top HalfTen          for(inti=0;i<n;i++){ One              for(intj=0;j<2*n;j++){ A                 if(j<n-i) -System.out.print (""); -                 if(J>=n-i && j<=n+i) theSystem.out.print ("*"); -                 } - System.out.println (); -             } +         //print the lower half of the section -          for(inti=1;i<n;i++){ +System.out.print (""); A              for(intj=0;j<2*n-i;j++){ at                 if(j<i) -System.out.print (""); -                 if(J>=i && j<2*n-i-1) -System.out.print ("*"); -                 } - System.out.println (); in             } -         } to}

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Problem-Solving ideas: first the graph into two parts to look at, the first five elements a rule, after four lines a rule, the use of double for Loop, the first layer of control row, the second Level control column. The important thing is to find the right rules!

2. title: Seeking 1+2!+3!+...+20! and the

1  Public classsuibian{2      Public Static voidMain (string[] args) {3         Longsum = 0;4          for(inti=0;i<20;i++) {5Sum + = factorial (i+1);6         }7 System.out.println (sum);8         }9     //factorialTen     Private Static LongFactorial (intN) { One         intmult = 1; A          for(inti=1;i<n+1;i++) -Mult *=i; -         returnmult; the         } -}

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Program Analysis: Set factorial another function to avoid errors!

Java BASIC Programming questions