Baekjoon Online Judge 10986번 풀이
- 2. https://www.acmicpc.net/problem/10986 • N A1, A2, …, AN • M • , Ai + … + Aj M (i, j) • 1 ≤ N ≤ 106 • 2 ≤ M ≤ 103 • 0 ≤ Ai ≤ 109
- 3. https://www.acmicpc.net/problem/10986 • N^2 • O(N^2) = (10^6)^2 = 10^12 • 10^12 ≥ 1 • !
- 4. https://www.acmicpc.net/problem/10986 • Si = A1 + … + Ai • Ai + … + Aj = Sj – Si-‐1 • (Ai + … + Aj) % M = (Sj – Si-‐1) % M • (Ai + … + Aj) % M == 0 • (Sj – Si-‐1) % M == 0 • 0 • Sj % M == Si-‐1 % M
- 5. https://www.acmicpc.net/problem/10986 • • Sj % M == Si-‐1 % M • (i, j) . • cntk Si % M == k i • 0 ≤ k < M k • cntk * (cntk -‐ 1) / 2 .