minor refinement

Author: KHvic

Fenwick-Tree/fenwick_class.cpp

@@ -8,17 +8,15 @@ private: vector<int> ft;
         ft.assign(n + 1, 0);
     }
     int rsq(int b) {
-        b++;
         int sum = 0;
-        for (; b; b -= (b&-b)) sum += ft[b];
+        for (b++; b; b -= (b&-b)) sum += ft[b];
         return sum;
     }
     int rsq(int a, int b) {
         return rsq(b) - rsq(a-1);
     }
     void adjust(int k, int v) {
-        k++;
-        for (; k < (int)ft.size(); k += (k&-k)) ft[k] += v;
+        for (k++; k < (int)ft.size(); k += (k&-k)) ft[k] += v;
     }
 };
 

Sqrt-Decomposition/sqrt_block.cpp

@@ -8,7 +8,7 @@ struct SD{
     vector<vector<int>> cnt;
     vector<int> vals;
     SD(vector<int>& vals):vals(vals),n(vals.size()) {
-        len = sqrt(vals.size()) + 1;
+        len = sqrt(n) + 1;
         cnt = vector<vector<int>>(len, vector<int>(MAX));
         for(int i=0;i<n;i++) cnt[i/len][vals[i]]++;
     }