wadhwasahil's blog

Lazy Propagation in segment tree
By wadhwasahil, history, 9 years ago, In English

I know about segment trees. But here I am stuck.I want to set all the values within an interval [l,r] to a constant c. and now after doing all the updates on the array, I want to find a[i] where 0<i<=n.

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9 years ago, # |
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I want the ith element a[i] after many updations .

a[]={1,2,3,4,5};

query1=1 4 3 // this means change the value of all elements to 3 in the range [1,4] so after first query a becomes a[]={3,3,3,3,4,5};

query2= 3 4 1 // this means change the value of all elements to 4 in range [3,4] a become a[]={3,3,1,1,4,5}

so I want the value of a[3](which is 1 in this case) after many queries. Hope you guys understood the question.

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    9 years ago, # ^ |
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    You can use segment tree with lazy propogation for Kind of queries you have !

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