{"problem":{"name":"Ex - Sequence of Substrings","description":{"content":"You are given a string $S = s_1 s_2 \\ldots s_N$ of length $N$ consisting of $0$'s and $1$'s. Find the maximum integer $K$ such that there is a sequence of $K$ pairs of integers $\\big((L_1, R_1), (L_2,","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":5000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc240_h"},"statements":[{"statement_type":"Markdown","content":"You are given a string $S = s_1 s_2 \\ldots s_N$ of length $N$ consisting of $0$'s and $1$'s.\nFind the maximum integer $K$ such that there is a sequence of $K$ pairs of integers $\\big((L_1, R_1), (L_2, R_2), \\ldots, (L_K, R_K)\\big)$ that satisfy all three conditions below.\n\n*   $1 \\leq L_i \\leq R_i \\leq N$ for each $i = 1, 2, \\ldots, K$.\n*   $R_i \\lt L_{i+1}$ for $i = 1, 2, \\ldots, K-1$.\n*   The string $s_{L_i}s_{L_i+1} \\ldots s_{R_i}$ is **strictly lexicographically smaller** than the string $s_{L_{i+1}}s_{L_{i+1}+1}\\ldots s_{R_{i+1}}$.\n\n## Constraints\n\n*   $1 \\leq N \\leq 2.5 \\times 10^4$\n*   $N$ is an integer.\n*   $S$ is a string of length $N$ consisting of $0$'s and $1$'s.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n$S$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc240_h","tags":[],"sample_group":[["7\n0101010","3\n\nFor $K = 3$, one sequence satisfying the conditition is $(L_1, R_1) = (1, 1), (L_2, R_2) = (3, 5), (L_3, R_3) = (6, 7)$. Indeed, $s_1 = 0$ is strictly lexicographically smaller than $s_3s_4s_5 = 010$, and $s_3s_4s_5 = 010$ is strictly lexicographically smaller than $s_6s_7 = 10$.  \nFor $K \\geq 4$, there is no sequence $\\big((L_1, R_1), (L_2, R_2), \\ldots, (L_K, R_K)\\big)$ satisfying the condition."],["30\n000011001110101001011110001001","9"]],"created_at":"2026-03-03 11:01:13"}}