「NOIP2017」时间复杂度

#include<memory.h>
#include<ctype.h>
#include<iostream>
using namespace std;
const int N=1005;
char s[N],t[N],b[N],l[N],r[N],var[N];
int top,mx,m,w,T,sta[N];bool err,vis[N];
int main(){
    for(scanf("%d",&T);T--;mx=top=err=0,memset(vis,0,sizeof vis)){
        scanf("%d%s
",&m,t);
        if(t[2]=='n') sscanf(t+4,"%d",&w);else w=0;
        for(int x,y;m--;){
            gets(s);
            if(s[0]=='E'){
                if(!top)
                    err=true;
                else
                    vis[var[top--]]=false;
            }
            else{
                sscanf(s,"%*s%s%s%s",b,l,r);
                if(vis[b[0]]) err=true;vis[b[0]]=true;
                var[++top]=b[0];
                if(isdigit(l[0])){
                    if(isdigit(r[0])){
                        sscanf(l,"%d",&x);sscanf(r,"%d",&y);
                        if(x<=y)
                            sta[top]=sta[top-1];
                        else
                            sta[top]=-1e9;
                    }
                    else if(r[0]=='n'){
                        sta[top]=sta[top-1]+1;
                        mx=max(mx,sta[top]); 
                    }
                }
                else if(l[0]=='n'){
                    if(r[0]=='n')
                        sta[top]=sta[top-1];
                    else
                        sta[top]=-1e9;
                }
            }
        }
        if(err||top) puts("ERR");else
        if(mx==w) puts("Yes");else puts("No");
    }
    return 0;
}