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Micro-Drill #149 — Partition labels (last occurrence)

Hash Strategies Target: 10s

Map each char to its last index. Extend partition end greedily.

last = {c: i for i, c in enumerate(s)}
res = []
start = end = 0
for i, c in enumerate(s):
    end = max(end, last[c])
    if i == end:
        res.append(end - start + 1)
        start = i + 1

Type it from memory. Go.

Practice Problems

• 763. Partition Labels
• 56. Merge Intervals

Related Coding Drills

• Drill #74 — Partition labels Medium
• Drill #149 — Partition Labels Medium
• Drill #53 — First and last occurrence Medium