我正在学习算法并且很乐意学习。我的问题是这个,我不能使用C中的整数数据类型输出数字“600851475143”。所以我切换到双打。但输出为“0.0000”。有人可以告诉我我做错了什么吗?我只想扫描并打印双数据类型中的任何数字,然后我将专注于获得最高的素因子:)
#include <stdio.h>
#include <math.h>
int main()
{
double number;
double div = 2;
double highest = 2;
printf("Please input a number: ");
scanf("%lf", &number);
printf("\n You entered: %lf", &number);
while(number!=0){
if(fmod(number,div) != 0){div = div + 1;}
else{
number = number / div;
printf("\n %lf", div);
if(highest < div){highest = div;}
if(number == 1){break;}
}
}
printf("\n The highest number is %lf", highest);
return 0;}
我做了什么:
在谷歌搜索“扫描double in c”,了解到“%lf”是正确的方法,但程序没有显示任何内容。
我在Stackoverflow中检查了各种问题,如:
Why does scanf need lf for doubles
Reading in double values with scanf in c
Difference between float and double
Read and Write within a file in C (double it)
Reading and writing double precision from/to files
Reading in double values with scanf in c
http://www.technoburst.net/2011/07/reading-double-in-c-using-scanf.html
感谢您用您的知识启发我。
答案 0 :(得分:1)
问题在于功能printf("%lf",&number)
应为printf("%lf",number)
答案 1 :(得分:0)
使用带警告的编译器进行编译会显示问题:
dbl.c:13:31: warning: format specifies type 'double' but the argument has type
'double *' [-Wformat]
printf("\n You entered: %lf", &number);
~~~ ^~~~~~~
1 warning generated.
将该行更改为:
printf("\n You entered: %lf", number);
您正在尝试打印号码的地址而不是号码。
另外,尝试在最后添加换行符:
printf("\n The highest number is %lf\n", highest);
因为,您正在使用整数,但我建议您只使用long long
,假设您有一个C99编译器:
#include <stdio.h>
#include <math.h>
int main()
{
long long number;
long long div = 2;
long long highest = 2;
printf("Please input a number: ");
scanf("%lld", &number);
printf("\n You entered: %lld", number);
while(number!=0){
if(number % div != 0){div = div + 1;}
else{
number = number / div;
printf("\n %lld", div);
if(highest < div){highest = div;}
if(number == 1){break;}
}
}
printf("\n The highest number is %lld\n", highest);
return 0;}
为了便于阅读,您还可以重新格式化代码:
#include <stdio.h>
#include <math.h>
int main() {
long long number, div, highest;
div = highest = 2;
printf("Please input a number: ");
scanf("%lld", &number);
printf("\n You entered: %lld", number);
while(number != 0) {
if (number % div != 0) div += 1;
else {
number /= div;
printf("\n %lld", div);
if (highest < div) highest = div;
if (number == 1) break;
}
}
printf("\n The highest number is %lld\n", highest);
return 0;
}
我还建议以不同的方式处理新行,这会让你:
#include <stdio.h>
#include <math.h>
int main() {
long long number, div, highest;
div = highest = 2;
printf("Please input a number: ");
scanf("%lld", &number);
printf("\n You entered: %lld\n", number);
while(number != 0) {
if (number % div != 0) div += 1;
else {
number /= div;
printf("%lld\n", div);
if (highest < div) highest = div;
if (number == 1) break;
}
}
printf("The highest number is %lld\n", highest);
return 0;
}