func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 100005;   int n, act;   int t[MAXN];   int last[MAXN], len[MAXN];   int main() {     scanf( %d , &n);     for (int i = 1; i < MAXN; ++i) len[i] = -1;     for (int i = 1; i <= n; ++i) {       scanf( %d , &t[i]);       act = t[i];       if (len[act] == -1) {         len[act] = 0;       } else if (len[act] >= 0) {         if (len[act] == 0)           len[act] = i - last[act];         else if (i - last[act] != len[act])           len[act] = -2;       }       last[act] = i;     }     int counter = 0;     for (int i = 1; i < MAXN; ++i)       if (len[i] >= 0) ++counter;     printf( %d n , counter);     for (int i = 1; i < MAXN; ++i) {       if (len[i] >= 0) {         printf( %d %d n , i, len[i]);       }     }     return 0;   }   