#include "testlib.h" #include #include #include using namespace std; int A; // Reads an answer (jury or participant) from 'stream', checks its validity // under the problem rules, and returns the sequence length. // On any invalidity, quits with _wa if stream==ouf, or _fail if stream==ans. int readAns(InStream &stream) { // Read claimed length int k = stream.readInt(1, 100000, "length"); if (k < 2) { stream.quitf(_wa, "length must be at least 2, found %d", k); } // Read the sequence vector s(k); for (int i = 0; i < k; i++) { char buf[50]; sprintf(buf, "seq[%d]", i+1); // allow large range to catch negatives or too large values s[i] = stream.readInt(-1000000000, 1000000000, buf); } // Check first element equals A if (s[0] != A) { stream.quitf(_wa, "first element must be %d, found %d", A, s[0]); } // Check second element is a positive integer in [1, A] if (s[1] <= 0 || s[1] > A) { stream.quitf(_wa, "second element must be between 1 and %d, found %d", A, s[1]); } // Check recurrence and non-negativity for (int i = 2; i < k; i++) { if (s[i] < 0) { stream.quitf(_wa, "sequence[%d] is negative: %d", i+1, s[i]); } int expected = s[i-2] - s[i-1]; if (s[i] != expected) { stream.quitf(_wa, "sequence[%d] is incorrect: expected %d, found %d", i+1, expected, s[i]); } } // Ensure maximality: the next term would be negative int nxt = s[k-2] - s[k-1]; if (nxt >= 0) { stream.quitf(_wa, "sequence is not maximal, can be extended with %d", nxt); } return k; } int main(int argc, char *argv[]) { registerTestlibCmd(argc, argv); // Read input A = inf.readInt(); // 1 <= A <= 30000 // Read jury and participant answers int jlen = readAns(ans); int plen = readAns(ouf); // Compare lengths if (plen < jlen) { quitf(_wa, "length is not maximal: expected %d, found %d", jlen, plen); } if (plen > jlen) { quitf(_fail, "participant has longer sequence than jury: jury %d, participant %d", jlen, plen); } // If equal, accept quitf(_ok, "length = %d", plen); return 0; }

코드 #5726