Data Structure Array: Given an array arr[], find the maximum j – i such that arr[j] > arr[i]

http://www.geeksforgeeks.org/given-an-array-arr-find-the-maximum-j-i-such-that-arrj-arri/

 1 #include <iostream>
 2 #include <vector>
 3 #include <algorithm>
 4 #include <queue>
 5 #include <stack>
 6 #include <string>
 7 #include <fstream>
 8 #include <map>
 9 using namespace std;
10 
11 int maxindexdiff(int arr[], int n) {
12     vector<int> L(n), R(n);
13     L[0] = arr[0];
14     for (int i = 1; i < n; i++) L[i] = min(L[i-1], arr[i]);
15     R[n-1] = arr[n-1];
16     for (int i = n-2; i >= 0; i--) R[i] = max(R[i+1], arr[i]);
17     int left, right, ans;
18     left = right = 0;
19     ans = -1;
20     while (left < n && right < n) {
21         if (L[left] < R[right]) {
22             ans = max(ans, right - left);
23             right++;
24         }
25         else left++;
26     }
27     return ans;
28 }
29 
30 int main() {
31     int arr[10] = {9, 2, 3, 4, 5, 6, 7, 8, 18, 0};
32     cout << maxindexdiff(arr, 10) << endl;
33     return 0;
34 }

posted @ 2014-04-08 12:23 ying_vincent 阅读(343) 评论(0) 收藏举报

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