A review of k-multiple inversion pairs, starting from a standard inversion-counting template and examining how a changed condition affects query boundaries and…
A review of simulating the lilac fractal: starting with the basic pattern, separating odd-step expansion from even-step rearrangement, and examining recurrence…
A review of Luogu P1121, using case analysis and a complementary formulation to turn a circular selection problem into linear DP, with an analysis and fix for…
A review of Luogu P1133, the Leader's Garden: starting with an incorrect linear DP model, examining the limits of patching circular constraints afterward, and…
A review of Luogu P8613, Children Queuing: connecting bubble sort to inversions, using a Fenwick tree to count the inversions involving each element, and exami…
Starting with increasing triples in Luogu P1637 and extending to strictly increasing subsequences of length k in SPOJ INCSEQ, this review develops a general ap…
A review of the Codeforces 1065 C1/C2 XOR games, starting from the invariant total XOR and examining how the most significant bit and the last critical index d…
A complete review of Lanqiao Cup 2026 Provincial Group B, from preparation and contest decisions to redoing the problems afterward, examining in-contest thinki…