func_code_string: #include <bits/stdc++.h>   using namespace std;   #define mod1  1000000007   #define mod2  998244353   #define ff   first   #define ss   second   #define int  long long   #define ll   unsigned long long   #define pb   push_back   #define mp   make_pair   #define pii  pair<int,int>   #define inf  9e18   #define N    15000005   #define pi   2*asin(1.0)   #define endl   n        void fast() {       ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);   #ifndef ONLINE_JUDGE       freopen( input.txt ,  r , stdin);       freopen( output.txt ,  w , stdout);   #endif   }            int32_t main() {       fast();       int t; cin>>t;       while(t--){           int n,m; cin>>n>>m;           int arr[n];           for(int i=0;i<n;i++){               cin>>arr[i];           }           int cnt=n;           int len=0;           for(int i=n-1;i>=0;i--){               if(arr[i]==cnt){                   cnt--;               }               else{                   len=i+1; break;               }           }           double ans=1.0;           for(int i=0;i<m;i++){               int r; double p;               cin>>r>>p;               if(r>=len){                   ans=(ans*(1.0-p));               }           }           ans=1.0-ans;           if(len==0) ans=1.0;           cout<<fixed<<setprecision(6)<<ans<<endl;       }       return 0;   }   