{"problem":{"name":"[蓝桥杯 2018 省 B] 递增三元组","description":{"content":"给定三个整数数组 $A = [A_1, A_2,\\cdots, A_N]$，$B = [B_1, B_2,\\cdots, B_N]$，$C = [C_1, C_2,\\cdots,C_N]$。 请你统计有多少个三元组 $(i, j, k)$ 满足： 1. $1 \\le i, j, k \\le N$   2. $A_i < B_j < C_k$","description_type":"Markdown"},"platform":"Luogu","limit":{"time_limit":1000,"memory_limit":262144},"difficulty":{"LuoguStyle":"P3"},"is_remote":true,"is_sync":true,"sync_url":null,"sign":"LGP8667"},"statements":[{"statement_type":"Markdown","content":"给定三个整数数组 $A = [A_1, A_2,\\cdots, A_N]$，$B = [B_1, B_2,\\cdots, B_N]$，$C = [C_1, C_2,\\cdots,C_N]$。\n\n请你统计有多少个三元组 $(i, j, k)$ 满足：\n1. $1 \\le i, j, k \\le N$  \n2. $A_i < B_j < C_k$\n\n## Input\n\n第一行包含一个整数 $N$。\n\n第二行包含 $N$ 个整数 $ A_1, A_2,\\cdots, A_N$。\n\n第三行包含 $N$ 个整数 $ B_1, B_2,\\cdots, B_N$。\n\n第四行包含 $N$ 个整数 $ C_1, C_2,\\cdots, C_N$。\n\n## Output\n\n一个整数表示答案。\n\n[samples]\n\n## Note\n\n对于 $30\\%$ 的数据，$1 \\le N \\le 100$。\n\n对于 $60\\%$ 的数据，$1 \\le N \\le 1000$。\n\n对于 $100\\%$ 的数据，$1 \\le N \\le 10^5$，$0 \\le A_i, B_i, C_i \\le 10^5$。","is_translate":false,"language":"English"}],"meta":{"iden":"LGP8667","tags":["动态规划 DP","2018","二分","枚举","蓝桥杯省赛"],"sample_group":[["3\n1 1 1\n2 2 2\n3 3 3","27"]],"created_at":"2026-03-03 11:09:25"}}