阿巴阿巴……

#include<iostream>
#include<iomanip>
#include<stdio.h>
#include<math.h>
#include<string>
#include<cstring>
using namespace std;
double n,tc,sum=0;//利润，提成，奖金
void js(double n,double tc,double bf1,double bf2){//bf1和bf2为判断部分
	if(n>bf1){
		if(n<bf2)sum+=(n-bf1)*tc;
		else sum+=(bf2-bf1)*tc;
	}else return;
}
int main(){
	cin>>n;
	js(n,0.1,0,100000);
	js(n,0.075,100000,200000);
	js(n,0.05,200000,400000);
	js(n,0.03,400000,600000);
	js(n,0.015,600000,1000000);
	js(n,0.01,1000000,pow(10,10));//这里的bf2没有上限，pow(a,b)=a的b次方
	printf("%.2lf",sum);
	return 0;
}

普通的if语句 （代码有亿点长，细品）

#include<bits/stdc++.h>
using namespace std;

int main(){
	int n;
	cin>>n;
	if(n<=100000){
		cout<<fixed<<setprecision(2)<<n*0.1;
	}
	if(100000<n&&n<=200000){
		cout<<fixed<<setprecision(2)<<10000+(n-100000)*0.075;
	}
	if(200000<n&&n<=400000){
		cout<<fixed<<setprecision(2)<<17500+(n-200000)*0.05;
	}
	if(400000<n&&n<=600000){
		cout<<fixed<<setprecision(2)<<27500+(n-400000)*0.03;
	}
	if(600000<n&&n<=1000000){
		cout<<fixed<<setprecision(2)<<33500+(n-600000)*0.015;
	}
	if(1000000<n){
		cout<<fixed<<setprecision(2)<<39500+(n-1000000)*0.01;
	}
	return 0;
}