C语言三四章实验作业

2

#include int main() {

float x;

printf(\请输入货物重量:\); scanf(\,&x); if(x>0&&x<=50) {

x=x*80; }

elseif(x>50&&x<=100) {

x=(x-50)*75+4000; }

elseif(x>100) {

x=(x-100)*70+(x-50)*75+4000; }

printf(\运费为:%f\\n\,x); return 0; }

3

#include int main() {

float x,y;

printf(\); scanf(\,&x); if(x<=0) { y=x; }

elseif(x>0&&x<1) {

y=2.0*x; }

elseif(x>=1) {

y=3*x*x-6*x+7; }

printf(\,y); return 0; }