编程：鸡、兔子问题：鸡兔共30只，脚共有90个。编写一个程序，求鸡、兔各多少只。

#include<iostream>

using namespace std;

int main()
{
int ji, tu;

for (ji=0; ji<=30; ji++)
{
tu = 30 - ji;
if (ji*2 + tu*4 == 90)
{
cout << "ji = " << ji << " tu = " << tu << endl;
}
}

system("pause");
return 0;
}

Dim a As Integer
Dim b As Integer
For a = 1 To 45
For b = 1 To 22
If a + b = 30 And a * 2 + b * 4 = 90 Then
msgbox "鸡有" & a & "只" & vbcrlf & "兔有" & b & "只"
End If
Next
Next

CLS
FOR JI=0 TO 30
TU=30-JI
IF JI*2+TU*4=90 THEN PRINT "JI:";JI,"TU:";TU
NEXT
END