counting numbers

Author: specialtactics

week1/counting-elements.cpp

@@ -0,0 +1,21 @@
+ class Solution {
+public:
+ int countElements(vector<int>& arr) {
+ map<int, int> counter;
+ int totals = 0;
+ 
+ for (vector<int>::iterator it = arr.begin(); it != arr.end(); ++it) {
+ ++(counter[(*it)]);
+ }
+ 
+ // Get rid of dups
+ sort(arr.begin(), arr.end());
+ vector<int>::iterator newEnd = unique(arr.begin(), arr.end());
+ 
+ for (vector<int>::iterator it = arr.begin(); it != newEnd; ++it) {
+ totals += counter[(*it)-1];
+ }
+ 
+ return totals;
+ }
+};