标签:nbsp mod toc 简单方法 out 简单 char value dbi
Given an integer n
, return the decimal value of the binary string formed by concatenating the binary representations of 1
to n
in order, modulo 109 + 7
.
Example 1:
Input: n = 1 Output: 1 Explanation: "1" in binary corresponds to the decimal value 1.
Example 2:
Input: n = 3 Output: 27 Explanation: In binary, 1, 2, and 3 corresponds to "1", "10", and "11". After concatenating them, we have "11011", which corresponds to the decimal value 27.
Example 3:
Input: n = 12 Output: 505379714 Explanation: The concatenation results in "1101110010111011110001001101010111100". The decimal value of that is 118505380540. After modulo 109 + 7, the result is 505379714.
Constraints:
1 <= n <= 105
class Solution { public int concatenatedBinary(int n) { int mod = 1_000_000_007; int sum = 0; for(int i = 1; i <= n; i++) { String cur = Integer.toBinaryString(i); for(char c : cur.toCharArray()) { int val = (c == ‘0‘) ? 0 : 1; sum = ((sum) * 2 % mod + val) % mod; } } return sum; } }
简单方法,就一个一个算,但是每个数的每一位sum都要*2更新,也要mod
1680. Concatenation of Consecutive Binary Numbers
标签:nbsp mod toc 简单方法 out 简单 char value dbi
原文地址:https://www.cnblogs.com/wentiliangkaihua/p/14338835.html