c2

1sem/adaptation courses/09/27.cpp

@@ -0,0 +1,43 @@
+// ac_9_27.cpp
+// Горбацевич Андрей
+#include <iostream>
+#include <fstream>
+#include <vector>
+
+using namespace std;
+
+inline int sign(int i) {
+    return (i < 0? -1 : 1);
+}
+
+int count_sign_changes(const vector<int> &vec) {
+    int c = 0;
+    for (size_t i = 1; i < vec.size(); i++) {
+        c += sign(vec[i-1]) != sign(vec[i]);
+    }
+    return c;
+}
+
+vector<int> read_vec(istream &reader) {
+    vector<int> out;
+    while (!reader.eof() && reader.good()) {
+        int i;
+        reader >> i;
+        out.push_back(i);
+    }
+    return out;
+}
+
+// -5 1 1 -5 1
+int main() {
+    ifstream inf("in.txt");
+    if (!inf.is_open())
+    {
+        cerr << "Unable to open file" << endl;
+        return 1;
+    }
+    vector<int> v = read_vec(inf);
+    int c = count_sign_changes(v);
+    cout << "Count of changes: " << c << endl;
+    return 0;
+}