《Cracking the Coding Interview》——第5章：位操作——题目1

2014-03-19 05:45

题目：给定两个数M和N，将N按照二进制位，覆盖到M的特定段位中去。

解法：位操作，请看代码。

代码：

 // 5.1 Insert one number into the certain bit segment of another number.

 #include <cstdio>

 using namespace std;

 void printBinary(unsigned num)

 {

     unsigned bit =  << ;

     do {

         putchar('' + !!(num & bit));

         bit >>= ;

     } while (bit);

 }

 unsigned insertBits(unsigned n, unsigned m, int ll, int rr)

 {

     return (n >> (rr + ) << (rr + )) + (m << ll) + (n - (n >> ll << ll));

 }

 int main()

 {

     unsigned n, m;

     unsigned res;

     int low, high;

     while (scanf("%u%u", &n, &m) == ) {

         scanf("%d%d", &low, &high);

         res = insertBits(n, m, low, high);

         printBinary(n);

         putchar('\n');

         printBinary(m);

         putchar('\n');

         printBinary(res);

         putchar('\n');

     }

     return ;

 }