clear?all?
x=-100:1:100;
h1=100;
h2=200;
V1=1500;
i1=5;
i2=10;
f=i1*pi/180;
s=i2*pi/180;
V2=V1/sin（f）;
V3=V2/sin（s）;
t0=2*（h1/V1+（h2-h1）/V2）;
V0=sqrt（（h1*V1+（h2-h1）*V2）/（h1/V1+（h2-h1）/V2））;
t1=abs（x）./V1;
t2=2*sqrt（（x/2）.*（x/2）+h1*h1）/V1;
t4=2*sqrt（t0*t0+x.*x/V0）;
fm=2*h1*tan（f）;
k=1;
for?i=1:length（x）;
????if?x（i）<-fm
????????t3_1（k）=2*h1*cos（f）/V1+abs（x（i））/V2;
????????x1（k）=x（i）;
????????k=k+1;
????end
end
k=1;
for?i=1:length（x）;
if?x（i）>fm
????????t3_2（k）=2*h1*cos（f）/V1+abs（x（i））/V2;
????????x2（k）=x（i）;
????????k=k+1;
????end
end
xm=2*（h1*ta