New Problems

Author: narkarum

src/chapter18divideandconquer/All_PeakFinder_1D_Linear_Search.java

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+public class All_PeakFinder_1D_Linear_Search{
+
+  public static void findPeak(int[] A) {
+
+    if (A == null || A.length == 0) {
+      return;
+    }
+    int n = A.length;
+
+    for (int i = 0; i < n; i++){
+      int left = 0, right = 0;
+      if (i > 0){
+        left = A[i - 1];
+      }
+      if (i < A.length - 1){
+        right = A[i + 1];
+      }
+      if (left <= A[i] && A[i] >= right){
+        System.out.println(A[i] + "");
+      }
+  	}
+  }
+
+public static void main(String[] args) {
+    int[] A = { 35, 5, 20, 2, 40, 25, 80, 25, 15, 40 };
+    findPeak(A);
+  }
+}

src/chapter18divideandconquer/Highest_PeakFinder_1D_Linear_Search.java

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+public class Highest_PeakFinder_1D_Linear_Search{
+
+  public static Integer findPeak(int[] A) {
+
+    if (A == null || A.length == 0) {
+      return null;
+    }
+
+    int n = A.length;
+    int peak = A[0];
+    for (int i = 1; i < n-1; i++){
+      if (A[i - 1] <= A[i] && A[i] >= A[i + 1]){
+        peak = A[i];
+      }
+  	}
+    if (peak < A[A.length-1]){
+      peak = A[A.length-1];
+    }
+    return peak;
+  }
+
+public static void main(String[] args) {
+    int[] A = { 35, 5, 20, 2, 40, 25, 80, 25, 15, 40 };
+    Integer peak = findPeak(A);
+    System.out.println(peak != null ? "Peak Element is "  + peak : "No peak element!" );
+  }
+}

src/chapter18divideandconquer/PeakFinder_1D_Binary_Search.java

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+public class PeakFinder_1D_Binary_Search{
+
+  public static Integer findPeak(int[] A) {
+    if (A == null || A.length == 0) {
+      return null;
+    }
+
+    int left = 0, right = A.length - 1, mid;
+    while (left + 1 < right){
+      mid = left + (right - left) / 2;
+      if (A[mid] < A[mid - 1]){
+        right = mid;
+      }
+      else if (A[mid] < A[mid + 1]){
+        left = mid;
+      }
+      else{
+        return mid;
+      }
+    }
+    if (A[left] > A[right]){
+      mid = left;
+    }
+    else{
+      mid = right;
+    }
+    return mid;
+  }
+
+public static void main(String[] args) {
+  int[] A = { 35, 5, 20, 2, 40, 25, 80, 25, 15, 40 };
+  Integer peak = findPeak(A);
+  System.out.println(peak != null ? "Peak Element is "  + A[peak] : "No peak element!" );
+  }
+}

src/chapter18divideandconquer/PeakFinder_1D_Linear_Search.java

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+public class PeakFinder_1D_Linear_Search{
+
+  public static Integer findPeak(int[] A) {
+
+    if (A == null || A.length == 0) {
+      return null;
+    }
+
+    int n = A.length;
+    int peak = A[0];
+    for (int i = 1; i < n; i++){
+      if (A[i - 1] <= A[i] && A[i] >= A[i + 1]){
+        peak = A[i];
+        return peak;
+      }
+  	}
+    if (peak < A[A.length-1]){
+      peak = A[A.length-1];
+    }
+    return null;
+  }
+
+public static void main(String[] args) {
+    int[] A = { 35, 5, 20, 2, 40, 25, 80, 25, 15, 40 };
+    Integer peak = findPeak(A);
+    System.out.println(peak != null ? "Peak Element is "  + peak : "No peak element!" );
+  }
+}