• None
• Graph Theory
• 2-SAT
• Articulation/Bridge/Biconnected Component
• Cycles/Topological Sorting/Strongly Connected Component
• Shortest Path
• Bellman Ford
• Dijkstra/Floyd Warshall
• Euler Trail/Circuit
• Heavy-Light Decomposition
• Minimum Spanning Tree
• Stable Marriage Problem
• Trees
• Directed Minimum Spanning Tree
• Flow/Matching
• Graph Matching
• Bipartite Matching
• Hopcroft–Karp Bipartite Matching
• Weighted Bipartite Matching/Hungarian Algorithm
• Flow
• Max Flow/Min Cut
• Min Cost Max Flow
• DFS-like
• Backtracking with Pruning/Branch and Bound
• Basic Recursion
• IDA* Search
• Parsing/Grammar
• Breadth First Search/Depth First Search
• Advanced Search Techniques
• Binary Search/Bisection
• Ternary Search
• Geometry
• Basic Geometry
• Computational Geometry
• Convex Hull
• Pick's Theorem
• Game Theory
• Green Hackenbush/Colon Principle/Fusion Principle
• Nim
• Sprague-Grundy Number
• Matrix
• Gaussian Elimination
• Matrix Exponentiation
• Data Structures
• Basic Data Structures
• Binary Indexed Tree
• Binary Search Tree
• Hashing
• Orthogonal Range Search
• Range Minimum Query/Lowest Common Ancestor
• Segment Tree/Interval Tree
• Trie Tree
• Sorting
• Disjoint Set
• String
• Aho Corasick
• Knuth-Morris-Pratt
• Suffix Array/Suffix Tree
• Math
• Basic Math
• Big Integer Arithmetic
• Number Theory
• Chinese Remainder Theorem
• Extended Euclid
• Inclusion/Exclusion
• Modular Arithmetic
• Combinatorics
• Group Theory/Burnside's lemma
• Counting
• Probability/Expected Value
• Others
• Tricky
• Hardest
• Unusual
• Brute Force
• Implementation
• Constructive Algorithms
• Two Pointer
• Bitmask
• Beginner
• Discrete Logarithm/Shank's Baby-step Giant-step Algorithm
• Greedy
• Divide and Conquer
• Dynamic Programming
• Tag it!

3
1
2
3

1
3
6

#include<stdio.h>
int main()
{int t;scanf("%d",&t);while(t--){int k;long long n;scanf("%lld",&n);k=n%9;n-=k;long long  sum;sum=n/9*45;//1~9的数位和为45for(int i=1;i<=k;i++)sum+=i;printf("%lld\n",sum%10000);}return 0;
}