Simplify Path

class Solution {
public:
    string simplifyPath(string path) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        int len = path.length();
        int cwpos = -1, cstart = 0, cend = 0;
        while (true) {
            while (cstart < len && path[cstart] == ‘/‘) ++cstart;
            if (cstart >= len) break;
            cend = cstart + 1;
            while (cend < len && path[cend] != ‘/‘) ++cend;
            int clen = cend - cstart;
            if (clen > 0 && (clen != 1 || path[cstart] != ‘.‘)) {
                if (clen == 2 && path[cstart] == ‘.‘ && path[cstart + 1] == ‘.‘) {
                    while (cwpos >= 0 && path[cwpos] != ‘/‘) --cwpos;
                    if (cwpos >= 0)
                        --cwpos;
                } else {
                    path[++cwpos] = ‘/‘;
                    while (cstart < cend) {
                        path[++cwpos] = path[cstart++];
                    }
                }
            }
            
            cstart = cend;
        }
        
        if (cwpos < 0) return "/";
        path.resize(cwpos + 1);
        return path;
    }
};