算法笔记codeup-Contest100000568

A

#include <stdio.h>
int main()
{
    int a=100;
    int sum=0;
    while(a)
    {
        sum=sum+a;
        a--;
    }
    printf("%d",sum);
    return 0;
}

B 差不多

C

#include <stdio.h>
int main()
{
    int a=100;
    int sum=0;
    for (;a>=1;a--) {
        /* code */
        sum+=a;
    }
    printf("%d",sum);
}

D

#include <stdio.h>
int main()
{
    int a=0;
    int sum=0;
    scanf("%d",&a);
    for (;a>=1;a--) {
        /* code */
        sum+=a;
    }
    printf("%d",sum);
}

E

#include <stdio.h>
int main()
{
    int a=1;
    int sum=0;
    for (;a<=10000;a++) {
        /* code */
        sum+=a;
        if(sum>1000)
        break;
    }
    printf("%d",a);
}

 F

 #include <stdio.h>

 int main()
 {
     int i=0;
     for(i=1;i<=4;i++)
     {    
         printf("%3d",1*i);
         printf("%3d",2*i);
         printf("%3d",3*i);
         printf("%3d",4*i);
         printf("%3d
",5*i);
     }
     
     
 } 

G

#include<stdio.h>
#include<math.h>
int main()
{
int sign=1;
double pi=0.0,n=1.0,term=1.0;
while(fabs(term)>=1e-6)
{
pi=pi+term;
n=n+2;
sign=-sign;
term=sign/n;
}
pi=pi*4;
printf("PI=%10.8f
",pi);
return 0;
}

H

#include <stdio.h>
#include <math.h>  
 int main()
 {
      int A=1;
     int B=1;
     int C=0;
     int count=0;
     int init=0;
     int chushu=0;
     int yushu=0;
     
 
     scanf("%d",&count);
     chushu=count/3;
     yushu=count%3;
     if(count==1||count==2)
     {
         printf("1");
     }
     else{
         for(;init<chushu;init++)
         {
             C=A+B;
             A=B+C;
             B=C+A;
         }
         switch(yushu)
         {
             case 0:
             printf("%d",C);
             break;
            case 1:
             printf("%d",A);
             break;
            case 2:
             printf("%d",B);
             break;
          } 
     }
     
 } 

I

#include <stdio.h>
#include <math.h>  
 int main()
 {
      double A=1.0;
     double B=2.0;
     int count=20;
     int temp=0;
     int init=0;
     double sum=0.0; 
     
     for(;init<20;init++)
     {
         sum+=B/A;
         temp=B;
         B=A+B;
         A=temp;
     }

     printf("%.6lf",sum);
     
 }