UPDATEIT - Update the array !
You have an array containing n elements initially all 0. You need to do a number of update operations on it. In each update you specify l, r and val which are the starting index, ending index and value to be added. After each update, you add the 'val' to all elements from index l to r. After 'u' updates are over, there will be q queries each containing an index for which you have to print the element at that index.
First line consists of t, the number of test cases. (1 <= t <= 10)
Each test case consists of "n u",number of elements in the array and the number of update operations, in the first line (1 <= n <= 10000 and 1 <= u <= 100000)
Then follow u lines each of the format "l r val" (0 <= l,r < n, 0 <= val <=10000)
Next line contains q, the number of queries. (1 <= q <= 10000)
Next q lines contain an index (0 <= index < n)
For each test case, output the answers to the corresponding queries in separate lines.
0 1 7
2 4 6
1 3 2
Difference array technique gives overall O(n) .
I had written a code of complexity O(u+n+q) but still getting tle in java. Can anyone tell me why?
Use the fact that updates occur before queries and you can do it without BIT ;)
can be solved without using segment tree or BIT.
Don't forget to use scanf and printf
Using Fewick Trees/Bit trees does the job .
10 Lines Code. Only Basic Logic Needed:)
First BIT question & AC in one go!
Segment tree + lazy propagation would do.