Add Segment-Tree Problem: Lucky Queries.

Author: manosriram

Graphs/Floyd-Warshall.cpp

@@ -0,0 +1,70 @@
+#include <iostream>
+#define INF INT_MAX
+using namespace std;
+int dist[64][64], adj[64][64];
+
+void setDistances(int n) {
+   for (int t=1;t<=n;++t) {
+        for (int j=1;j<=n;++j) {
+            if (t == j) dist[t][j] = 0;
+            else if (adj[t][j]) dist[t][j] = adj[t][j];
+            else dist[t][j] = INF;
+        }
+   } 
+   return;
+}
+
+void Floyd(int n) {
+    for (int k=1;k<=n;++k) {
+        for (int t=1;t<=n;++t) {
+             for (int j=1;j<=n;++j) {
+                 dist[t][j] = min(dist[t][j], (dist[t][k] + dist[k][j]));
+             }
+        } 
+    }
+    return;
+}
+
+void addEdge(int src, int dest, int wt) {
+    adj[src][dest] = wt;
+    adj[dest][src] = wt;
+}
+
+void initGraph(int n) {
+    for (int t=1;t<=n;++t) {
+        for (int j=1;j<=n;++j) {
+            if (t == j) adj[t][j] = 0;
+            else adj[t][j] = INF;
+        }
+    }
+    return;
+}
+
+int main() {
+    int n = 5;
+    initGraph(n);
+
+    addEdge(1, 2, 5);    
+    addEdge(1, 4, 9);    
+    addEdge(1, 5, 1);    
+    addEdge(2, 3, 2);    
+    addEdge(3, 2, 2);    
+    addEdge(3, 4, 7);    
+    addEdge(4, 1, 9);    
+    addEdge(4, 3, 7);    
+    addEdge(4, 5, 2);    
+    addEdge(5, 1, 1);    
+    addEdge(5, 4, 2);    
+
+    setDistances(n);
+    Floyd(n);
+
+    for (int t=1;t<=n;++t) {
+        for (int j=1;j<=n;++j) {
+            cout << dist[t][j] << " ";
+        }
+        cout << "\n";
+    }
+
+}
+

Segment-Tree/Problems/a.out

@@ -0,0 +1,71 @@
+#include <iostream>
+#include <string.h>
+#define MAX_ 1000
+using namespace std;
+int tree[MAX_] = {0};
+int lazy[MAX_] = {-1};
+
+int diff(int st, int ed, int x) {
+    return (ed - x - (st - 1));
+}
+
+void Build(string arr, int st, int ed, int treeNode) {
+    if (st == ed) {
+        if (arr[st] == '4')
+            tree[treeNode] = 1;
+        else
+            tree[treeNode] = 0;
+
+        return;
+    }
+
+    int mid = (st + ed)/2;
+    Build(arr, st, mid, 2 * treeNode);
+    Build(arr, mid+1, ed, (2*treeNode)+1);
+
+    tree[treeNode] = tree[2 * treeNode] + tree[(2*treeNode)+1];
+}
+
+void lazyUpdate(string arr, int st, int ed, int qs, int qe, int treeNode) {
+    if (lazy[treeNode] != -1) {
+        tree[treeNode] = lazy[treeNode];
+
+        if (st != ed) {
+            tree[2*treeNode] = diff(st, ed, tree[2*treeNode]);
+            tree[(2*treeNode)+1] = diff(st, ed, tree[(2*treeNode)+1]);
+        }
+        lazy[treeNode] = -1;
+    }
+    if (st > qe || ed < qs) return;
+
+    if (st >= qs && ed <= qe) {
+        tree[treeNode] = diff(st, ed, tree[treeNode]);
+
+        if (st != ed) {
+            tree[2 * treeNode] = diff(st, ed, tree[2 * treeNode]);
+            tree[(2 * treeNode)+1] = diff(st, ed, tree[(2*treeNode)+1]);
+        }
+        return;
+    }
+    int mid = (st + ed)/2;
+    lazyUpdate(arr, st, mid, qs, qe, 2 * treeNode);
+    lazyUpdate(arr, mid+1, ed, qs, qe, (2 * treeNode)+1);
+
+    tree[treeNode] = tree[2 * treeNode] + tree[(2*treeNode)+1];
+}
+
+int main() {
+    string arr = "47447747";
+    int n = arr.length();
+
+    Build(arr, 0, n-1, 1);
+
+    for (int t=1;t<2*n;++t)
+        cout << tree[t] << " ";
+
+    cout << endl;
+    lazyUpdate(arr, 0, n-1, 1, 4, 1);
+
+    for (int t=1;t<2*n;++t)
+        cout << tree[t] << " ";
+}