C++=>Data Structures=>Tree=>B+_Tree.cpp

Author: DIVYA-KUMARI1

C++/Data Structures/Tree/B+_Tree.cpp

@@ -0,0 +1,154 @@
+#include<iostream>
+using namespace std;
+struct BplusTree {
+ int *d;
+ BplusTree **child_ptr;
+ bool l;
+ int n;
+}*r = NULL, *np = NULL, *x = NULL;
+BplusTree* init()//to create nodes {
+ int i;
+ np = new BplusTree;
+ np->d = new int[6];//order 6
+ np->child_ptr = new BplusTree *[7];
+ np->l = true;
+ np->n = 0;
+ for (i = 0; i < 7; i++) {
+ np->child_ptr[i] = NULL;
+ }
+ return np;
+}
+
+void traverse(BplusTree *p)//traverse tree {
+ cout<<endl;
+ int i;
+ for (i = 0; i < p->n; i++) {
+ if (p->l == false) {
+ traverse(p->child_ptr[i]);
+ }
+ cout << " " << p->d[i];
+ }
+ if (p->l == false) {
+ traverse(p->child_ptr[i]);
+ }
+ cout<<endl;
+}
+
+void sort(int *p, int n)//sort the tree {
+ int i, j, t;
+ for (i = 0; i < n; i++) {
+ for (j = i; j <= n; j++) {
+ if (p[i] >p[j]) {
+ t = p[i];
+ p[i] = p[j];
+ p[j] = t;
+ }
+ }
+ }
+}
+
+int split_child(BplusTree *x, int i) {
+ int j, mid;
+ BplusTree *np1, *np3, *y;
+ np3 = init();
+ np3->l = true;
+ if (i == -1) {
+ mid = x->d[2];
+ x->d[2] = 0;
+ x->n--;
+ np1 = init();
+ np1->l = false;
+ x->l = true;
+ for (j = 3; j < 6; j++) {
+ np3->d[j - 3] = x->d[j];
+ np3->child_ptr[j - 3] = x->child_ptr[j];
+ np3->n++;
+ x->d[j] = 0;
+ x->n--;
+ }
+ for (j = 0; j < 6; j++) {
+ x->child_ptr[j] = NULL;
+ }
+ np1->d[0] = mid;
+ np1->child_ptr[np1->n] = x;
+ np1->child_ptr[np1->n + 1] = np3;
+ np1->n++;
+ r = np1;
+ } else {
+ y = x->child_ptr[i];
+ mid = y->d[2];
+ y->d[2] = 0;
+ y->n--;
+ for (j = 3; j <6 ; j++) {
+ np3->d[j - 3] = y->d[j];
+ np3->n++;
+ y->d[j] = 0;
+ y->n--;
+ }
+ x->child_ptr[i + 1] = y;
+ x->child_ptr[i + 1] = np3;
+ }
+ return mid;
+}
+
+void insert(int a) {
+ int i, t;
+ x = r;
+ if (x == NULL) {
+ r = init();
+ x = r;
+ } else {
+ if (x->l== true && x->n == 6) {
+ t = split_child(x, -1);
+ x = r;
+ for (i = 0; i < (x->n); i++) {
+ if ((a >x->d[i]) && (a < x->d[i + 1])) {
+ i++;
+ break;
+ } else if (a < x->d[0]) {
+ break;
+ } else {
+ continue;
+ }
+ }
+ x = x->child_ptr[i];
+ } else {
+ while (x->l == false) {
+ for (i = 0; i < (x->n); i++) {
+ if ((a >x->d[i]) && (a < x->d[i + 1])) {
+ i++;
+ break;
+ } else if (a < x->d[0]) {
+ break;
+ } else {
+ continue;
+ }
+ }
+ if ((x->child_ptr[i])->n == 6) {
+ t = split_child(x, i);
+ x->d[x->n] = t;
+ x->n++;
+ continue;
+ } else {
+ x = x->child_ptr[i];
+ }
+ }
+ }
+}
+ x->d[x->n] = a;
+ sort(x->d, x->n);
+ x->n++;
+}
+
+int main() {
+ int i, n, t;
+ cout<<"enter the no of elements to be inserted\n";
+ cin>>n;
+ for(i = 0; i < n; i++) {
+ cout<<"enter the element\n";
+ cin>>t;
+ insert(t);
+ }
+ cout<<"traversal of constructed B tree\n";
+ traverse(r);
+}