func_code_string: #include <bits/stdc++.h>   int n, p[4005], f[4005][4005], w[4005], tl;   void solve() {     scanf( %d , &n);     n <<= 1;     for (int i = 1; i <= n; ++i) scanf( %d , &p[i]);     tl = 0;     int pre = 1;     w[++tl] = 1;     for (int i = 2; i <= n; ++i) {       if (p[i] < p[pre])         w[tl]++;       else {         pre = i;         w[++tl] = 1;       }     }     for (int i = 0; i <= n; ++i)       for (int j = 0; j <= n; ++j) f[i][j] = 0;     f[0][0] = 1;     for (int i = 1; i <= tl; ++i)       for (int j = 0; j <= n; ++j)         f[i][j] = f[i - 1][j] | (j - w[i] >= 0 ? f[i - 1][j - w[i]] : 0);     if (f[tl][n / 2])       puts( YES );     else       puts( NO );   }   int main() {     int t;     scanf( %d , &t);     while (t--) solve();   }   