Differences

This shows you the differences between two versions of the page.

--- cpp:stl:vector [2020/05/27 16:54] – [Ένθεση στον πίνακα] gthanos
+++ cpp:stl:vector [2020/05/27 16:56] – gthanos
@@ Line 108: / Line 108: @@
 <code cpp vector_erase_02.cpp>
+#include <vector>
+#include <list>
+#include <iostream>
+#include <iomanip>
+using namespace std;
+template<typename T>
+void print(vector<T> v) {
+  for(auto it = v.cbegin(); it!=v.cend(); it++)
+    cout << setw(3) << *it;
+  cout << endl;
+}
+int main() {
+  vector<int> ints;                  // initially zero size
+  for(int i=0; i<10; i++) {
+    ints.push_back(i+1);             // insert to the end - very fast
+    ints.insert(ints.begin(),i+1);   // insert to the beginning - extremely slow
+  }
+  print(ints);
+  while(ints.size() > 0) {
+    ints.erase(ints.begin());    // erase the first element.
+    ints.erase(ints.end()-1);    // erase the laste element.
+    print(ints);
+  }
+}
+</code>
+<code cpp vector_erase_03.cpp>
 #include <vector>
 #include <list>
@@ Line 138: / Line 169: @@
   while(ints.size() > 0) {
-    ints.erase(ints.begin());    // erase the first element.
+    ints.erase(ints.begin(), ints.end());    // erase everything!
-    ints.erase(ints.end()-1);    // erase the laste element.
     print(ints);
   }