func_code_string: #include <bits/stdc++.h>   using namespace std;   struct Query {     int id, left, right, time, blockLeft, blockRight;     Query()         : id(-1), left(-1), right(-1), time(-1), blockLeft(-1), blockRight(-1) {}     Query(int id, int left, int right, int time, int blockLeft, int blockRight)         : id(id),           left(left),           right(right),           time(time),           blockLeft(blockLeft),           blockRight(blockRight) {}     bool operator<(const Query &otherQuery) const {       if (blockLeft != otherQuery.blockLeft) {         return blockLeft < otherQuery.blockLeft;       }       if (blockRight != otherQuery.blockRight) {         return blockRight < otherQuery.blockRight;       }       return time < otherQuery.time;     }   };   struct Operation {     int pos, oldValue, newValue;     Operation() : pos(-1), oldValue(-1), newValue(-1) {}     Operation(int pos, int oldValue, int newValue)         : pos(pos), oldValue(oldValue), newValue(newValue) {}   };   void del(int value, int *cnts, int *saveValues) {     saveValues[cnts[value]]--;     cnts[value]--;     saveValues[cnts[value]]++;   }   void add(int value, int *cnts, int *saveValues) {     saveValues[cnts[value]]--;     cnts[value]++;     saveValues[cnts[value]]++;   }   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int n, q;     cin >> n >> q;     int sqrtValue = pow(n, 2.0 / 3.0), *values = new int[n + 1],         *tmpValues = new int[n + 1];     if (sqrtValue == 0) sqrtValue = 1;     vector<int> disValues;     for (int i = 1; i <= n; i++) {       cin >> values[i];       tmpValues[i] = values[i];       disValues.push_back(values[i]);     }     Query *querys = new Query[q + 1];     Operation *opts = new Operation[q + 1];     int cntQuerys = 0, cntOpts = 0;     for (int i = 1; i <= q; i++) {       int opt;       cin >> opt;       if (opt == 1) {         int left, right;         cin >> left >> right;         ++cntQuerys;         querys[cntQuerys] = Query(cntQuerys, left, right, cntOpts,                                   left / sqrtValue, right / sqrtValue);       } else {         int pos, value;         cin >> pos >> value;         ++cntOpts;         opts[cntOpts] = Operation(pos, tmpValues[pos], value);         tmpValues[pos] = value;         disValues.push_back(value);       }     }     sort(disValues.begin(), disValues.end());     disValues.resize(unique(disValues.begin(), disValues.end()) -                      disValues.begin());     for (int i = 1; i <= cntOpts; i++) {       Operation &tmpOpt = opts[i];       tmpOpt.oldValue =           lower_bound(disValues.begin(), disValues.end(), tmpOpt.oldValue) -           disValues.begin();       tmpOpt.newValue =           lower_bound(disValues.begin(), disValues.end(), tmpOpt.newValue) -           disValues.begin();     }     for (int i = 1; i <= n; i++) {       values[i] = lower_bound(disValues.begin(), disValues.end(), values[i]) -                   disValues.begin();     }     int valueSize = static_cast<int>(disValues.size()),         *cnts = new int[valueSize + 3], *saveValues = new int[n + 2];     memset(cnts, 0, sizeof(int) * (valueSize + 3));     memset(saveValues, 0, sizeof(int) * (n + 2));     int *results = new int[cntQuerys + 1];     sort(querys + 1, querys + cntQuerys + 1);     int l = 1, r = 0, time = 0;     for (int i = 1; i <= cntQuerys; i++) {       Query &tmpQuery = querys[i];       while (r < tmpQuery.right) {         r++;         add(values[r], cnts, saveValues);       }       while (l > tmpQuery.left) {         l--;         add(values[l], cnts, saveValues);       }       while (r > tmpQuery.right) {         del(values[r], cnts, saveValues);         r--;       }       while (l < tmpQuery.left) {         del(values[l], cnts, saveValues);         l++;       }       while (time < tmpQuery.time) {         time++;         Operation &tmpOpt = opts[time];         if (tmpOpt.pos >= l && tmpOpt.pos <= r) {           del(tmpOpt.oldValue, cnts, saveValues);           add(tmpOpt.newValue, cnts, saveValues);         }         values[tmpOpt.pos] = tmpOpt.newValue;       }       while (time > tmpQuery.time) {         Operation &tmpOpt = opts[time];         if (tmpOpt.pos >= l && tmpOpt.pos <= r) {           del(tmpOpt.newValue, cnts, saveValues);           add(tmpOpt.oldValue, cnts, saveValues);         }         values[tmpOpt.pos] = tmpOpt.oldValue;         time--;       }       for (int i = 1;; i++) {         if (i > n) {           results[tmpQuery.id] = 0;         }         if (saveValues[i] == 0) {           results[tmpQuery.id] = i;           break;         }       }     }     for (int i = 1; i <= cntQuerys; i++) {       cout << results[i] << endl;     }     return 0;   }   