样例解释：`第七个程序第一重循环无法进入，故为常数复杂度。`
by zjpwdyf @ 2023-10-18 13:36:00
```cpp
#include<cstdio>
#include<stack>
#include<string>
#include<iostream>
#include<algorithm>
using namespace std;
const int maxl=105;
int t,l,w;
string o;
string code[maxl];
int sread(int &x,string c){
int res=0;
int len=c.size();
while(c[x]<'0' || c[x]>'9'&&x<c.size()){
if(c[x]=='n'){
++x;
return 1000000;
}
++x;
}
while(c[x]>='0' && c[x]<='9'){
res*=10;res+=c[x]-'0';
++x;
}
return res;
}
int geto(){
int res=0,x=3;
int len=o.size();
if(o[2]=='n') res=sread(x,o);
else res=0;
return res;
}
int check(){
int res=0,now=0;
int a,b,x;
stack<int> s;
int flag=-1;
bool ins[26]={0};
bool ef[26]={0};
for(int i=1;i<=l;i++){
if(code[i][0]=='F'){
int k=code[i][2]-'a';
if(ins[k]) return -1;
s.push(k);ins[k]=true;
x=4;
a=sread(x,code[i]);b=sread(x,code[i]);
if(b-a>1000) {
if(flag==-1){
now++;
res=max(res,now);
ef[k]=true;
}
}
if(a>b){
if(flag==-1) flag=k;
}
}
if(code[i][0]=='E'){
if(s.empty()) return -1;
int k=s.top();
s.pop();ins[k]=false;
if(flag==k) flag=-1;
if(ef[k]){
ef[k]=false;
now--;
}
}
}
if(s.size()) return -1;
return res;
}
int main(){
scanf("%d",&t);
while(t--){
int ww;
scanf("%d ",&l); getline(cin,o);
w=geto();
for(int i=1;i<=l;i++) getline(cin,code[i]);
ww=check();
if(ww==-1) puts("ERR");
else{
if(ww==w) puts("Yes");
else puts("No");
}
}
}
```
by quxiangyu @ 2024-01-24 20:03:52