3007. 价值和小于等于 K 的最大数字

3007. 价值和小于等于 K 的最大数字

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题目链接：3007. 价值和小于等于 K 的最大数字

代码如下：

//参考链接：https://leetcode.cn/problems/maximum-number-that-sum-of-the-prices-is-less-than-or-equal-to-k/solutions/2603673/er-fen-da-an-shu-wei-dpwei-yun-suan-pyth-tkir
class Solution 
{
public:long long findMaximumNumber(long long k, int x) {auto check=[&](long long num){long long res=0;int i=x-1;for(long long n=num>>i;n;n>>=x,i+=x){res+=(n/2)<<i;if(n%2){long long mask=(1LL<<i)-1;res+=(num&mask)+1;}}return res<=k;};//二分long long left=0,right=(k+1)<<x;while(left+1<right){long long mid=left+(right-left)/2;(check(mid)?left:right)=mid;}return left;}
};