2311. 小于等于 K 的最长二进制子序列

2311. 小于等于 K 的最长二进制子序列

丑陋的代码，边界问题改半天

class Solution {
public:
    int calc(string s){
        int x = 0;
        for(auto c: s){
            x <<= 1;
            if(c=='1') x+=1;
        }
        return x;
    }
    int longestSubsequence(string s, int k) {
        int one = 0, zero = 0;
        int n = s.size();

        if(n > 31) {
            for(int i = 0; i < n - 31; i++ ) {
                if(s[i] == '1') one++;
            }
            s = s.substr(n-31);
        }
        int cur = calc(s);
        if(cur<=k) return n - one;
        for(int i =0; i < s.size(); i++) {
            cur = calc(s.substr(i));
            if(cur <= k) return n - one;
            if(s[i] == '1') one++;
        }
        return 0;
    }
};