第五十一题
Write a C function which does the addition of two integers without using the '+' operator. You can use only the bitwise operators.(Remember the good old method of implementing the full-adder circuit using the or, and, xor gates....)
题目讲解： 参考：
http://www.geeksforgeeks.org/add-two-numbers-without-using-arithmetic-operators/
int Add(int x, int y)
{
// Iterate till there is no carry
while (y != )
{
// carry now contains common set bits of x and y
int carry = x & y; // Sum of bits of x and y where at least one of the bits is not set
x = x ^ y; // Carry is shifted by one so that adding it to x gives the required sum
y = carry << ;
}
return x;
}
或
int Add(int x, int y)
{
if (y == )
return x;
else
return Add( x ^ y, (x & y) << );
}
第五十二题
How do you print I can print % using the printf function? (Remember % is used as a format specifier!!!)
题目讲解： 参考：
http://www.geeksforgeeks.org/how-to-print-using-printf/
printf("%%");
printf("%c", '%');
printf("%s", "%");
第五十三题
What's the difference between the following two C statements?
const char *p;
char* const p;
题目讲解：
const char *p:
p指向的值只读；
char* const p:
p的值只读；
第五十四题
What is the difference between memcpy and memmove?
题目讲解：
对重叠区域(overlapping regions)的处理有区别。
第五十五题
What is the format specifiers for printf to print double and float values?
题目讲解：
double: %lf
float: %f
第五十六题
Write a small C program to determine whether a machine's type is little-endian or big-endian.
题目讲解：
参考：
http://www.geeksforgeeks.org/little-and-big-endian-mystery/
unsigned int determine_endian()
{
unsigned int i = ;
char *c = (char *)&i;
if (*c)
return ;//little endian
else
return ;//big endian
}
第五十七题
Write a C program which prints Hello World! without using a semicolon!!!
题目讲解：
#include <stdio.h> int main()
{
while(printf(“Hello World!”)<)
{}
}