#include <bits/stdc++.h>   #define rep(i, a, b) for (int i = a; i <= b; i++)   #define per(i, a, b) for (int i = a; i >= b; i--)   using namespace std;      typedef unsigned long long ull;   typedef pair <int, int> pii;   typedef long long ll;      template <typename T>   inline void read(T &f) {       f = 0; T fu = 1; char c = getchar();       while (c <  0  || c >  9 ) { if (c ==  - ) { fu = -1; } c = getchar(); }       while (c >=  0  && c <=  9 ) { f = (f << 3) + (f << 1) + (c & 15); c = getchar(); }       f *= fu;   }      template <typename T>   void print(T x) {       if (x < 0) putchar( - ), x = -x;       if (x < 10) putchar(x + 48);       else print(x / 10), putchar(x % 10 + 48);   }      template <typename T>   void print(T x, char t) {       print(x); putchar(t);   }      const int N = 3e5 + 5;      struct seg_t {       int mx[N << 2];          void build(int u, int l, int r) {           mx[u] = 0;           if (l == r) return;           int mid = (l + r) >> 1;           build(u << 1, l, mid);           build(u << 1 | 1, mid + 1, r);       }          void modify(int u, int l, int r, int x, int y) {           mx[u] = max(mx[u], y);           if (l == r) return;           int mid = (l + r) >> 1;           if (mid >= x) modify(u << 1, l, mid, x, y);           else modify(u << 1 | 1, mid + 1, r, x, y);       }          int query(int u, int L, int R, int l, int r) {           if (l <= L && R <= r) return mx[u];           int mid = (L + R) >> 1, ans = 0;           if (mid >= l) ans = max(ans, query(u << 1, L, mid, l, r));           if (mid + 1 <= r) ans = max(ans, query(u << 1 | 1, mid + 1, R, l, r));           return ans;       }   } tr, rmq;      set <int> pos;   set <int> :: iterator it;   int a[N], cando[N], lpos[N], pre[N], ans[N];   int T, n;      int main() {       read(T);       while (T--) {           read(n);           rmq.build(1, 1, n);           for (int i = 1; i <= n; i++) read(a[i]), rmq.modify(1, 1, n, i, min(n, i + a[i]));           tr.build(1, 1, n);           for (int i = n; i >= 1; i--) {               int r = min(i + a[i], n);               if (i + 1 <= r) tr.modify(1, 1, n, i, tr.query(1, 1, n, i + 1, r));               else tr.modify(1, 1, n, i, i);           }           for (int i = 1; i <= n + 1; i++) cando[i] = 0;           cando[1] = 1;           pos.clear();           for (int i = 2; i <= n; i++) {               if (cando[i - 1]) pos.insert(i - 1);               it = pos.lower_bound(i - a[i]);               if (it != pos.end()) {                   pre[i] = lpos[*it];                   int r = i - 1;                   if (lpos[*it] != *it) r = rmq.query(1, 1, n, *it, i - 1);                   else if (*it + 1 <= i - 1) r = rmq.query(1, 1, n, *it + 1, i - 1);                   if (r >= i + 1) r = tr.query(1, 1, n, i + 1, r);                   if (!cando[r + 1]) {                       cando[r + 1] = 1;                       lpos[r + 1] = i;                   }                   if (r == n) break;               }           }           if (cando[n + 1]) {               printf( YES n );               for (int i = 1; i <= n; i++) ans[i] = 0;               int now = lpos[n + 1];               while (now) {                   ans[now] = 1;                   now = pre[now];               }               for (int i = 1; i <= n; i++) {                   if (ans[i]) putchar( L );                   else putchar( R );               }               putchar(  n );           } else {               printf( NO n );           }       }       return 0;   }