feat: ternary search was added

LuchoBazz · web-flow · commit a30d9ed02294 · 2022-08-22T09:04:50.000-05:00
diff --git a/searches/searches_ternary_search_I.cpp b/searches/searches_ternary_search_I.cpp
@@ -0,0 +1,20 @@
+double ternary_search(const function<double(double)> &func, double low, double high) {
+    int it = 0;
+    while (it < 100) { // with 50 iterations it has precision for 1e-9
+        double diff = (high - low) / 3.0;
+        double mid1 = low + diff;
+        double mid2 = high - diff;
+
+        double f1 = func(mid1);
+        double f2 = func(mid2);
+
+        if (f1 > f2) // change to < to find the maximum
+            low = mid1;
+        else
+            high = mid2;
+        it++;
+    }
+    return func(low);
+}
+// Usage:
+// double ans = ternary_search(funct1, low, high);
diff --git a/searches/searches_ternary_search_II.cpp b/searches/searches_ternary_search_II.cpp
@@ -0,0 +1,20 @@
+// This version is slower than the iterations version.
+double ternary_search(const function<double(double)> &func, double low, double high) {
+    double eps = 1e-9;
+    while (high - low > eps) {
+        double diff = (high - low) / 3.0;
+        double mid1 = low  + diff;
+        double mid2 = high - diff;
+
+        double f1 = func(mid1);
+        double f2 = func(mid2);
+
+        if (f1 > f2) // change to < to find the maximum
+            low = mid1;
+        else
+            high = mid2;
+    }
+    return func(low);
+}
+// Usage:
+// double ans = ternary_search(funct1, low, high);
