ngk_manh's blog

Help needed Range Updates and Sum CSES
By ngk_manh, history, 4 years ago, In English

Hi guy, i am stucking in this problem : https://cses.fi/problemset/task/1735/

Here is my code : https://cses.fi/paste/567abb6bc35edc71146fae/

I have no idea why i got WA. Can anybody explain for me what was wrong in my concept ?

(Sorry because my English:"((( )

UPD : I got AC, my code has a big mistake follow smax said below.

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4 years ago, # |
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Lines 50-53:

it[l].sum = it[id].sv*(mid-st+1);
it[r].sum = it[id].sv*(se-mid);
it[l].ic = it[r].ic = 0;
it[id].sv = 0;

You set the left and right child's sums, but then you don't propagate it[id].sv to it[l].sv and it[r].sv, so any children underneath the left and right children don't get set properly.

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