求指正错误我看了很久也改了很久但就是不能解决

#include<stdio.h>
int main()
{
    int x,y,z,sum,b,n;
    double price,first,second,three;
    scanf("%d %d",&x,&y);
    b=x;n=y;
    sum=x+y;
    if(sum<=2760){
        price=0.538*y;
        printf("%.2f",price);
    }
    else if(2760<sum&&sum<=4800){
        if(x<=2760)
        {    
            z=2760-x;
            b=y-z;
            first=0.538*z;
            second=0.588*b;
            price=first+second;
            printf("%.2f",price);
        }
        else{
            price=y*0.588;
            printf("%.2f",price);
        }
    }
    else if(sum>4800)
    {
        if(x<=2760){
            b=2760-x;
            first=0.538*b;
            second=0.588*2040;
            z=y-4800;
            three=z*0.838;
            price=first+second+three;
            printf("%.2f",price);
        }
        else if(x>2760&&x<=4800){
            b=4800-x;
            first=0.588*b;
            z=y-b;
            second=0.838*z;
            price=first+second;
            printf("%.2f",price);
        }
        else if(x>4800)
        {
            first=y*0.838;
            printf("%.2f",first);
        }
    }
}

0.538*y

你的逻辑写得太复杂了，应该从最高档往下算比较简洁些

#include <stdio.h>

double calculate_fee(double x) {
  double bands[] = {2760.0, 4800.0};
  double rates[] = {0.538, 0.588, 0.838};
  double sum = 0.0;
  if (x > bands[1]) {
    sum += (x - bands[1]) * rates[2];
    x = bands[1];
  }
  if (x > bands[0]) {
    sum += (x - bands[0]) * rates[1];
    x = bands[0];
  }
  sum += x * rates[0];
  return sum;
}

int main() {
  double x, y;
  scanf("%lf%lf", &x, &y);
  printf("%.2lf", calculate_fee(x + y) - calculate_fee(x));
  return 0;
}