Applying Parallel Computation Algorithms in the Design of Serial Algorithms
Exact 1-D grouping DP and parametric minimisation of the tilt dual (2 Sep 2026)
Added by the independent DS19 audit (AUDITS/AUDIT-DS-PRACTICAL-CERTIFIED-SOLVER-001.md).
- Wang & Song (2011) implement the contiguous 1-D -means DP in time and space — exactly the fixed-tilt evaluation DS19.2 describes.
- Grønlund et al. (2017, arXiv:1701.07204; pp. 1–2 read) survey the exact 1-D problem: the DP recurrence runs in , or on sorted input, by monotone-matrix search, and the weighted discrete scalar quantization form is covered. Transfers: the fixed-tilt bound is after sorting. Does not transfer: exact ties of tilted values are not treated; the audit's tie lemma (report §7.2) shows the DP value is tie-order independent.
- Megiddo (1983) parametric search and Toledo (1993; primary text
read) fixed-dimension concave maximisation with polynomial comparisons.
With and the interval DP as a degree-2 evaluator, the exact tilt
dual minimum is computable with polynomially many arithmetic operations for
fixed and variable . Does not transfer: neither
source bounds bit complexity; at the audit's root-separation
bisection supplies a polynomial-bit algorithm (report §7.5), and
OPEN-DS-TILT-DUAL-EXACT-COMPLEXITYretains the bit question for fixed and the whole question for variable . - Carstensen (1983; secondary record) is the original
parametric shortest-path breakpoint construction behind the
Gajjar–Radhakrishnan warning: the envelope must not be materialised, which
parametric search avoids.
See
LITERATURE/audits/AUDIT-DS-PRACTICAL-CERTIFIED-SOLVER-2-September-2026.mdfor the six-field table.
J. ACM 30(4):852-865 (primary record checked 2 Sep 2026). Parametric search: simulate a comparison algorithm at the unknown optimal parameter and resolve comparisons at polynomial roots with a monotone sign oracle. At d_lambda=1 it lifts the fixed-tilt interval DP to an arithmetic-polynomial exact minimiser of the tilt dual; bit complexity is not analysed there (AUDIT-DS-PRACTICAL-CERTIFIED-SOLVER supplies it).
Cited by
- Publication-grade audit of the DS19 tilt-DP certificate complexAUDIT-DS-PRACTICAL-CERTIFIED-SOLVER
- Scalar-POI tilt-DP gives a valid two-sided certificate with an exact saddle closure gateDS-TILT-DUAL-CERTIFICATE
- Best practical Ds solver with theorem-backed certificateOPEN-DS-PRACTICAL-CERTIFIED-SOLVER
- Exact bit complexity of the variable-dimension tilt-DP dualOPEN-DS-TILT-DUAL-EXACT-COMPLEXITY