func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 100010, MAXC = 500;   int can[MAXC], c = 0;   int n, m, a[MAXN], b[MAXN];   int t[MAXN][MAXC];   int main() {     cin >> n >> m;     for (int i = 0; i < n; i++) cin >> a[i];     memcpy(b, a, sizeof(b));     sort(b, b + n);     for (int i = 0; i < n; i++) {       int end = i;       while (b[end] == b[i]) end++;       if (end - i >= b[i]) can[c++] = b[i];       i = end - 1;     }     for (int i = 0; i < n; i++) {       for (int j = 0; j < c; j++) {         t[i + 1][j] = t[i][j];         if (a[i] == can[j]) t[i + 1][j]++;       }     }     int l, r;     for (int i = 0; i < m; i++) {       cin >> l >> r;       int ans = 0;       for (int j = 0; j < c; j++)         if (t[r][j] - t[l - 1][j] == can[j]) ans++;       cout << ans << endl;     }     return 0;   }   