关于看不懂为什么CE

#include<bits/stdc++.h>
using namespace std;
struct var
{
    int start,stop;
    bool idx;
    tt(int start,int stop,bool idx)
    {
        this->start=start;
        this->stop=stop;
        this->idx=idx
    }
};queue<var>q;
const int sz=2e5+5;
bool usd[sz];
bool QreadB()
{
    while(true)
    {char c=getchar();if(c=='0' or c=='1')return c-'0';}
}
int main()
{
    var tt;tt=var(1,1,QreadB())
    for(int i=2;i<=n;++i)
    {
        bool obj=QreadB();
        if(obj==tt.idx)++tt.stop;
        else
        {
            q.push(tt);tt=var(i,i,obj);
        }
    }
    q.push(tt);while(true)
    {
        //delete
        queue<var>qq;
        while(q.size())
        {
            var it=q.front();q.pop();
            while(usd[it.start])++it.start;
            cout<<idx<<' ';++it.start;
            qq.push(it);usd[it.start-1]=true;
        }
        //clear empty
        q=queue<var>();
        while(qq.size())
        {
            var it=qq.front();qq.pop();
            if(it.start>=it.stop)continue;
            else q.push(it);
        }
        //check has
        if(q.empty())break;cout<<endl;
        //combination
        vector<var>vc;vc.push(q.front());
        q.pop();while(q.size())
        {
            var id=q.front();q.pop();
            if(id.idx==vc.back().idx)
            {
                var it=vc.back();vc.pop_back();
                id.stop=it.stop;
            }
            vc.push_back(id);
        }
    }
}

/tmp/compiler_jch1z68m/src:7:35: 错误：ISO C++ 不允许声明无类型的‘tt’ [-fpermissive]
    7 |     tt(int start,int stop,bool idx)
      |                                   ^
/tmp/compiler_jch1z68m/src: 在成员函数‘int var::tt(int, int, bool)’中:
/tmp/compiler_jch1z68m/src:11:22: 错误：expected ‘;’ before ‘}’ token
   11 |         this->idx=idx
      |                      ^
      |                      ;
   12 |     }
      |     ~                 
/tmp/compiler_jch1z68m/src:12:5: 警告：在有返回值的函数中未发现 return 语句 [-Wreturn-type]
   12 |     }
      |     ^
/tmp/compiler_jch1z68m/src: 在函数‘int main()’中:
/tmp/compiler_jch1z68m/src:23:31: 错误：no matching function for call to ‘var::var(int, int, bool)’
   23 |     var tt;tt=var(1,1,QreadB())
      |                               ^
/tmp/compiler_jch1z68m/src:3:8: 附注：candidate: ‘var::var()’
    3 | struct var
      |        ^~~
/tmp/compiler_jch1z68m/src:3:8: 附注： 备选需要 0 实参，但提供了 3 个
/tmp/compiler_jch1z68m/src:3:8: 附注：candidate: ‘constexpr var::var(const var&)’
/tmp/compiler_jch1z68m/src:3:8: 附注： 备选需要 1 实参，但提供了 3 个
/tmp/compiler_jch1z68m/src:3:8: 附注：candidate: ‘constexpr var::var(var&&)’
/tmp/compiler_jch1z68m/src:3:8: 附注： 备选需要 1 实参，但提供了 3 个
/tmp/compiler_jch1z68m/src:24:17: 错误：‘i’在此作用域中尚未声明
   24 |     for(int i=2;i<=n;++i)
      |                 ^
/tmp/compiler_jch1z68m/src:24:20: 错误：‘n’在此作用域中尚未声明
   24 |     for(int i=2;i<=n;++i)
      |                    ^
/tmp/compiler_jch1z68m/src:41:19: 错误：‘idx’在此作用域中尚未声明
   41 |             cout<<idx<<' ';++it.start;
      |                   ^~~
/tmp/compiler_jch1z68m/src:53:9: 警告：this ‘if’ clause does not guard... [-Wmisleading-indentation]
   53 |         if(q.empty())break;cout<<endl;
      |         ^~
/tmp/compiler_jch1z68m/src:53:28: 附注：...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
   53 |         if(q.empty())break;cout<<endl;
      |                            ^~~~
/tmp/compiler_jch1z68m/src:55:26: 错误：‘class std::vector<var>’ has no member named ‘push’
   55 |         vector<var>vc;vc.push(q.front());
      |                          ^~~~