我来个C语言的:
#include
main(){
float x;
scanf("%f",&x);
if (x<0) printf("invalid\n");
else printf("%f\n",sqrt(x));
}
运行结果如下:
16
4.000000
-5
invalid
QBASIC呀,早说呀:
INPUT X
IF X<0 THEN
PRINT "无意义"
ELSE
PRINT "算术平方根是:",SQR(X)
END IF
Pascal语言:
program ex;
var
a:real;
begin
readln(a);
if a<=0 then writeln('无意义')
else writeln(sqrt(a));
readln;
end.
QBASIC的
cls
a=0
input"输入一个数",a
if a<0 then print"无意义"
else print"a的平方根为",sqr(a)
QBASIC的
CLS
INPUT A
IF A<0 THEN PRINT"无意义" ELSE PRINT "A=";SQR(A)
END