求指教！为啥这个程序vc可以输出结果在Dev-cpp运行到scanf那里就不走了
求指教！为什么这个程序vc可以输出结果在Dev-cpp运行到scanf那里就不走了
#include<stdio.h>
#include<math.h>
int main()
{
unsigned int a=0;
printf("Enter a postive integer: ");
scanf("%d",&a);
int i=1,
j=1,
n=0,
sum=0,
c=a,
b=0;
do
{
n=pow(10,i);
b=(c%n)/(n/10);
c-=b*(n/10);
i++;
}
while(c!=0);
c=a;
do
{
n=pow(10,j);
b=(c%n)/(n/10);
c-=b*(n/10);
sum+=b*pow(10,i-2);
j++;
i--;
}
while(i>=0);
printf("The number %d reserved is %d rebmun ehT.",a,sum);
return 0;
}
编译器为vc++6。0
Dev-c++5.4.1
------解决方案--------------------
执行没问题啊
------解决方案--------------------
gcc下执行的确没问题
我的C-Free执行的确出不来结果，我单步时发现n在i等于2时变成了99而不是100，不知道是不是编译器问题——
楼主不妨单步一下VC6和dev试试，看看有什么不同
------解决方案--------------------
我觉得可能是unsigned int和%d不匹配造成的问题。楼主可以试试这两个改动：
1.
unsigned int a=0;
scanf("%u",&a);
2.
int a=0;
scanf("%d",&a);
一般情况下unsigned int和%d混用都问题不大，dev-cpp不知道有什么不一样。
顺便说一句，我刚入行的时候曾经这么干过：
short a;
scanf("%d", &a);
结果就把栈弄崩了，自己还不知道是怎么回事。从那以后就觉得scanf太危险了（其实该说指针太危险了）
------解决方案--------------------
pow
Calculates x raised to the power of y.
double pow( double x, double y );
Routine Required Header Compatibility
pow <math.h> ANSI, Win 95, Win NT
For additional compatibility information, see Compatibility in the Introduction.
Libraries
LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version
Return Value
pow returns the value of xy. No error message is printed on overflow or underflow.
Values of x and y Return Value of pow
x < > 0 and y = 0.0 1
x = 0.0 and y = 0.0 1
x = 0.0 and y < 0 INF
Parameters
x
Base
y
Exponent
Remarks
The pow function computes x raised to the power of y.
pow does not recognize integral floating-point values greater than 264, such as 1.0E100.
Example
/* POW.C
*
*/
#include <math.h>
#include <stdio.h>
void main( void )
{
double x = 2.0, y = 3.0, z;
z = pow( x, y );
printf( "%.1f to the power of %.1f is %.1f\n", x, y, z );
}
Output
2.0 to the power of 3.0 is 8.0
Floating-Point Support Routines
See Also exp, log, sqrt
http://bbs.****.net/topics/390676437
#include<stdio.h>
#include<math.h>
int main()
{
unsigned int a=0;
printf("Enter a postive integer: ");
scanf("%d",&a);
int i=1,
j=1,
n=0,
sum=0,
c=a,
b=0;
do
{
n=pow(10,i);
b=(c%n)/(n/10);
c-=b*(n/10);
i++;
}
while(c!=0);
c=a;
do
{
n=pow(10,j);
b=(c%n)/(n/10);
c-=b*(n/10);
sum+=b*pow(10,i-2);
j++;
i--;
}
while(i>=0);
printf("The number %d reserved is %d rebmun ehT.",a,sum);
return 0;
}
编译器为vc++6。0
Dev-c++5.4.1
------解决方案--------------------
执行没问题啊
------解决方案--------------------
gcc下执行的确没问题
我的C-Free执行的确出不来结果，我单步时发现n在i等于2时变成了99而不是100，不知道是不是编译器问题——
楼主不妨单步一下VC6和dev试试，看看有什么不同
------解决方案--------------------
我觉得可能是unsigned int和%d不匹配造成的问题。楼主可以试试这两个改动：
1.
unsigned int a=0;
scanf("%u",&a);
2.
int a=0;
scanf("%d",&a);
一般情况下unsigned int和%d混用都问题不大，dev-cpp不知道有什么不一样。
顺便说一句，我刚入行的时候曾经这么干过：
short a;
scanf("%d", &a);
结果就把栈弄崩了，自己还不知道是怎么回事。从那以后就觉得scanf太危险了（其实该说指针太危险了）
------解决方案--------------------
pow
Calculates x raised to the power of y.
double pow( double x, double y );
Routine Required Header Compatibility
pow <math.h> ANSI, Win 95, Win NT
For additional compatibility information, see Compatibility in the Introduction.
Libraries
LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version
Return Value
pow returns the value of xy. No error message is printed on overflow or underflow.
Values of x and y Return Value of pow
x < > 0 and y = 0.0 1
x = 0.0 and y = 0.0 1
x = 0.0 and y < 0 INF
Parameters
x
Base
y
Exponent
Remarks
The pow function computes x raised to the power of y.
pow does not recognize integral floating-point values greater than 264, such as 1.0E100.
Example
/* POW.C
*
*/
#include <math.h>
#include <stdio.h>
void main( void )
{
double x = 2.0, y = 3.0, z;
z = pow( x, y );
printf( "%.1f to the power of %.1f is %.1f\n", x, y, z );
}
Output
2.0 to the power of 3.0 is 8.0
Floating-Point Support Routines
See Also exp, log, sqrt
http://bbs.****.net/topics/390676437