用C语言编写程序，输入月薪salary，输出应交的个人所得税tax（保留2位小数）。按照2011年开始实行的新的个人所得税法，计算公式为： tax=rate*（salary - 3500）- deduction 当salary ≤ 3500时，rate = 0、deduction = 0； 当3500 ＜ salary ≤ 5000时，rate = 3%、deduction = 0； 当5000 ＜ salary ≤ 8000时，rate = 10%、deduction = 105； 当8000 ＜ salary ≤ 12500时，rate = 20%、deduction = 555； 当12500 ＜ salary ≤ 38500时，rate = 25%、deduction = 1005； 当38500 ＜ salary ≤ 58500时，rate = 30%、deduction = 2755； 当58500 ＜ salary ≤ 83500时，rate = 35%、deduction = 5505； 当83500 ＜ salary时，rate = 45%、deduction = 13505。

#include <stdio.h>

int main() {
double salary, rate, tax, deduction;

printf("请输入月薪: ");
scanf("%lf", &salary);

if (salary <= 3500) {
rate = 0;
deduction = 0;
} else if (salary <= 5000) {
rate = 0.03;
deduction = 0;
} else if (salary <= 8000) {
rate = 0.1;
deduction = 105;
} else if (salary <= 12500) {
rate = 0.2;
deduction = 555;
} else if (salary <= 38500) {
rate = 0.25;
deduction = 1005;
} else if (salary <= 58500) {
rate = 0.3;
deduction = 2755;
} else if (salary <= 83500) {
rate = 0.35;
deduction = 5505;
} else {
rate = 0.45;
deduction = 13505;
}

tax = (salary - 3500) * rate - deduction;
printf("应交个人所得税为: %.2lf\n", tax);

return 0;
}

程序会提示用户输入月薪, 然后根据输入的月薪使用if-else语句计算出应交的个人所得税。
最后通过printf输出,保留2位小数。