小弟刚学c,谁能告诉我怎么样将2.3 3.4之类的小数变成3和4 这样的整数

[mybreeze]

小弟刚学c,谁能告诉我怎么样将2.3 3.4之类的小数变成3和4 这样的整数，但是想原来是整数的3.0 4.0 还是3 和4
强制类型转换（int）+1不能解决3.0 4.0问题

[gwsr]

引用C语言的数学函数：floor(x) 向下取整 ，ceil(x) 向上取整

[ghtsao]

Example
/* FLOOR.C: This example displays the largest integers
* less than or equal to the floating-point values 2.8
* and -2.8. It then shows the smallest integers greater
* than or equal to 2.8 and -2.8.
*/

#include <math.h>
#include <stdio.h>

void main( void )
{
double y;

y = floor( 2.8 );
printf( "The floor of 2.8 is %f\n", y );
y = floor( -2.8 );
printf( "The floor of -2.8 is %f\n", y );

y = ceil( 2.8 );
printf( "The ceil of 2.8 is %f\n", y );
y = ceil( -2.8 );
printf( "The ceil of -2.8 is %f\n", y );
}

Output
The floor of 2.8 is 2.000000
The floor of -2.8 is -3.000000
The ceil of 2.8 is 3.000000
The ceil of -2.8 is -2.000000

放分哦

[hproof]

如果我想把 PI = 3.1415926535897932384626433832795028841971…… 这样的长数精确到小数点后n位，不知道 floor/ceil 能不能做?

像这样？

floor(pi, n);
florr(-pi, n);
...