Chef vs Bharat Solution | CHEFORA |CODECHEF JULY CHALLENGE
Chef and his friend Bharat have decided to play the game “The Chefora Spell”.
In the game, a positive integer NN (in decimal system) is considered a “Chefora” if the number of digits dd is odd and it satisfies the equationN=∑i=0d−1Ni⋅10i,N=∑i=0d−1Ni⋅10i,
where NiNi is the ii-th digit of NN from the left in 00-based indexing.
Let AiAi denote the ii-th largest Chefora number.
They’ll ask each other QQ questions, where each question contains two integers LL and RR. The opponent then has to answer with(∏i=L+1R(AL)Ai)mod109+7.(∏i=L+1R(AL)Ai)mod109+7.
Bharat has answered all the questions right, and now it is Chef’s turn. But since Chef fears that he could get some questions wrong, you have come to his rescue!
- The first line contains an integer QQ — the number of questions Bharat asks.
- Each of the next QQ lines contains two integers LL and RR.
Print QQ integers — the answers to the questions on separate lines.