我可以说我用70分钟做完所有然后ac全部吗？第一次遇到这么顺利的题，第二题二进制1的是程序员面试金典的题，第一题和第三题竟然直接手写没调试即ac 链接：http://www.nowcoder.com/practice/33ad4d168a3247b9b63f41e4eaded652?tpId=8&tqId=11021&rp=2&ru=/ta/cracking-the-coding-interview&qru=/ta/cracking-the-coding-interview/question-ranking class CloseNumber { public: vector<int> getCloseNumber(int x) { // write code here int i, j; int small, big; for(i = 0; i < 32 && (x & (1 << i)) != 0; ++i) ; if(i > 0) { big = x + (1 << (i - 1)); for(j = i ; j < 32 && (x & (1 << j)) == 0; ++j) ; //small = x - (j << (j - 1)); small = x & ~((1 << (j + 1)) - 1); for(int k = 0; k <= i; ++k) small |= (1 << (j - k - 1)); } else { for( ; i < 32 && (x & (1 << i)) == 0; ++i) ; for(j = i; j < 32 && (x & (1 << j)) != 0; ++j) ; big = x + (1 << i); for(int k = 0; k < j - i - 1; ++k) big |= (1 << k); small = x - (1 << (i - 1)); } return vector<int>({small, big}); } };