12 条题解

  • 1
    @ 2024-4-24 22:12:23
    #include <stdio.h>
    int main()
    {
        int n,i=1;
        double a,b,c=1.0;
        scanf("%d",&n);
        while(i<=n)
        {
            b=c/i;
            a=a+b;
            c=-c;
            i++;
        }
        printf("%.1lf",a);
        return 0;
    }
    //
    
    • 0
      @ 2025-10-26 18:03:37

      #include <stdio.h> #include <math.h> int main(){ int n; double sum=0; scanf("%d",&n); double arr[n]; for(int i=0;i<n;i++){ arr[i]=1/((i+1)*pow(-1,i)); } for(int j=0;j<n;j++){ sum+=arr[j]; } printf("%.1lf",sum); }

      • 0
        @ 2025-10-2 10:09:04
        #include <stdio.h>
        int main()
        {
            int a,b=1,c=1;
            double d=0;
            scanf("%d",&a);
            while (a--){
                d+=b*1.0/c;
                b=-b;
                c++;
            }printf("%.1lf",d);
        }
        
        • 0
          @ 2025-9-25 22:45:48

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


          **}**
          

          ** printf("%.1f",sum);**


          return 0; }

          • 0
            @ 2025-8-19 20:37:38

            #include<stdio.h> int main() { int N,i=1; scanf("%d",&N); double b=0; while(i<=N) { if(i%2==0) { b=b-1.0/i; i++; } else { b=b+1.0/i; i++; }

            }
            printf("%.1f",b);
            return 0;
            

            }

            • 0
              @ 2024-10-11 21:49:00

              #include<Stdio.h> int main() { int i,n=0; float sum=0; scanf("%d",&n); for(i=1;i<=n;i++) { if(i%2==0) sum=sum+1.0*(-1)/i; if(i%2!=0) sum=sum+1.0/i; } printf("%.1f",sum); }

              • 0
                @ 2023-9-19 19:19:10
                #include <stdio.h> 
                int main() 
                {
                    int i,n=0;
                    float sum=0;
                    scanf("%d",&n);
                    for(i= 1;i<=n;i++)
                    {
                        if(i%2==0)
                        sum=sum+1.0*(-1)/i;
                        if(i%2!=0)
                        sum=sum+1.0/i;
                        }
                    printf("%.1f",sum);
                    return 0;
                }
                
                • 0
                  @ 2023-8-21 19:19:12

                  #include <stdio.h> int main () { int i,sign; sign=1; int n; scanf("%d",&n); double m=0.0; for ( i=1;i<=n;i++) { m+=sign*1.0/i; sign=-sign; } printf("%.1f",m); return 0; }

                  • 0
                    @ 2023-8-14 15:24:18

                    #include<iostream>#include<iomanip> using namespace std; int main() {int i,n,a;

                    double sum;cin>>n;for(i=1;i<=n;i++)

                    {

                    //为什么必须将i的临时值赋给一个变量,对啊可以不用赋值

                    if(i%2==0)

                    sum=sum-(1.0/i);

                    else sum=sum+(1.0/i);

                    } cout << fixed << setprecision(1) << sum << endl;

                    return 0;}

                    • 0
                      @ 2022-10-6 10:27:02

                      #include<stdio.h> int main(){ int n; double a; scanf("%d",&n); for(int i=1;i<=n;i++){ if(i%2!=0){ a=a+1.0/i; } else if(i%2==0){ a=a-1.0/i; } } printf("%.1lf",a); return 0; }

                      • 0
                        @ 2022-9-27 16:21:21

                        #include<stdio.h>

                        int main(){

                        int n;

                        double sum=0,a=1;

                        scanf("%d",&n);

                        for(int i=1;i<=n;i++){

                        sum+=a/i;

                        a=-a;

                        } printf("%.1lf",sum);

                        return 0; }

                        • 0
                          @ 2022-9-26 16:33:48

                          #include<stdio.h>

                          int main(void)

                          { int n,i,s; scanf("%d",&n); float sum=0;

                          for(i=1;i<=n;i++){ s=i; if(s%2==0){ s=-i; }

                          sum=sum+(1.0/s); }

                          printf("%.1f",sum);

                          return 0;

                          }

                          • 1

                          信息

                          ID
                          31
                          时间
                          1000ms
                          内存
                          128MiB
                          难度
                          6
                          标签
                          递交数
                          5509
                          已通过
                          1742
                          上传者