1 files changed, 133 insertions, 0 deletions

diff --git a/2025/10/b-debug.py b/2025/10/b-debug.py
new file mode 100644
index 0000000..e6f9961
--- /dev/null
+++ b/2025/10/b-debug.py
@@ -0,0 +1,133 @@
+import fileinput
+from math import gcd
+
+inf = 999999999
+
+def readline(l):
+        b = [int(x) for x in l[l.index('{')+1:l.index('}')].split(',')]
+
+        A = [[] for j in b]
+        c = []
+
+        end = l.index(']')
+        while '(' in l[end:]:
+                begin = l[end:].index('(') + end + 1
+                end = l[begin:].index(')') + begin
+                bu = [int(x) for x in l[begin:end].split(',')]
+                c.append(min(b[j] for j in bu))
+                for i in range(len(b)):
+                        A[i].append(1 if i in bu else 0)
+
+        return A, b, c
+
+def printabc(A, b, c):
+        print("--")
+        for i in range(len(b)):
+                print(A[i], [b[i]])
+        print(f"Parameter bounds: {c}")
+        print("--")
+
+def swaprow(A, b, i, j):
+        if i != j:
+                A[i], A[j] = A[j], A[i]
+                b[i], b[j] = b[j], b[i]
+
+def swapcol(A, c, i, j):
+        if i != j:
+                for k in range(len(A)):
+                        A[k][i], A[k][j] = A[k][j], A[k][i]
+                c[i], c[j] = c[j], c[i]
+
+def reducerow(A, b, i, j):
+        if A[i][i] != 0:
+                x = A[i][i]
+                y = -A[j][i]
+                d = gcd(x, y)
+                A[j] = [(y*A[i][k]+x*A[j][k])//d for k in range(len(A[i]))]
+                b[j] = (y*b[i]+x*b[j])//d
+
+def reduce(A, b, c):
+        for i in range(len(A[0])):
+                # Swap columns until there is one in position i with at least
+                # one non-zero element.
+                I = []
+                k = i
+                while len(I) == 0 and k < len(A[0]):
+                        swapcol(A, c, i, k)
+                        I = [j for j in range(i, len(A)) if A[j][i] != 0]
+                        k += 1
+
+                # If no such column is found, we are done
+                if len(I) == 0:
+                        break
+
+                # Swap rows so that A[i][i] is non-zero
+                swaprow(A, b, i, I[0])
+
+                # Reduce all other rows
+                for j in range(i+1, len(A)):
+                        reducerow(A, b, i, j)
+
+        # Remove all rows of zero and check if the system is solvable
+        I = [i for i in range(len(A)) if any(a != 0 for a in A[i])]
+        if any(b[i] != 0 for i in range(len(A)) if i not in I):
+                printabc(A, b, c)
+                print("Unsolvable!")
+                exit(1)
+        A = [A[i] for i in I]
+        b = [b[i] for i in I]
+
+        # TODO continue with back substitution?
+        for i in range(len(A)-1, -1, -1):
+                for j in range(i):
+                        reducerow(A, b, i, j)
+
+        # Clean all rows to minimize coefficients (unnecessary, but makes
+        # numbers smaller).
+        for i in range(len(A)):
+                d = gcd(*A[i]) * (-1 if A[i][i] < 0 else 1)
+                A[i] = [A[i][k]//d for k in range(len(A[i]))]
+                b[i] = b[i]//d
+
+        return A, b, c
+
+def paramcomb(nparam, c):
+        if nparam == 0:
+                return [[]]
+
+        ret = []
+        for i in range(c[-nparam]+1):
+                ret += [[i, *l] for l in paramcomb(nparam-1, c)]
+        return ret
+
+def solve_system_min_sum(A, b, c):
+        #nparam = len(A[0])-len(A)
+        #print(f"{nparam}: {paramcomb(nparam, c)}")
+
+        k = len(A[0]) - len(A)
+        mins = inf
+        for c in paramcomb(k, c):
+                sol = sum(c)
+                for i in range(len(A)):
+                        p = sum(c[j]*A[i][len(A[0])-k+j] for j in range(len(c)))
+                        a = (b[i] - p)//A[i][i]
+                        if a < 0 or a*A[i][i] != b[i] - p:
+                                sol = inf
+                                break
+                        sol += a
+                mins = min(mins, sol)
+        return mins
+
+with fileinput.input() as lines:
+        sols = []
+        k = 1
+        for line in lines:
+                print(f"doing line {k}: {line[:-1]}")
+                A, b, c = readline(line)
+                #printabc(A, b, c)
+                A, b, c = reduce(A, b, c)
+                #printabc(A, b, c)
+                sols.append(solve_system_min_sum(A, b, c))
+                k += 1
+        print(sols)
+        print(sum(sols))