/* upsolve after reading analysis */ #include <stdio.h> #include <string.h> #define N 1234567 int sum(int n, int a, int b) { int m = n * 2 + 1, d = (b - a + m) % m; if (n % 2 == 0 && d % 2 == 0 && d < m - 1) return (a + d / 2) % m; if (n % 2 == 1 && (m - d) % 2 == 0 && d > 1) return (b + (m - d) / 2) % m; if (d == 1 || d == m - 1) return a; if (d == (n + 3) % m || d == (n - 1 + m) % m) return (a - n + m) % m; if (d == (n - 3 + m) % m || d == (n + 5) % m) return (b - n - 1 + m) % m; return -1; } int main() { int t, r; scanf("%d%d", &t, &r); if (r != 3) while (t--) { static int aa[N]; static char used[N * 2 + 1]; int n, m, i, s, a, b; scanf("%d", &n), m = n * 2 + 1; s = 0; for (i = 0; i < n; i++) { scanf("%d", &aa[i]); s = (s + aa[i]) % m; } memset(used, 0, m * sizeof *used); for (i = 0; i < n; i++) used[aa[i] = (aa[i] - s + m) % m] = 1; a = -1, b = -1; for (i = 1; i < n; i++) if (used[i] && used[m - i]) { if (n % 2 == 0) a = (m - i + s) % m, b = (i + s) % m; else a = (i + s) % m, b = (m - i + s) % m; break; } if (a == -1 && b == -1) { if (used[0] && used[1]) a = (0 + s) % m, b = (1 + s) % m; else if (used[0] && used[m - 1]) a = (0 + s) % m, b = (m - 1 + s) % m; else if (used[n] && used[2]) a = (n + s) % m, b = (2 + s) % m; else if (used[n] && used[m - 2]) a = (n + s) % m, b = (m - 2 + s) % m; else if (used[4] && used[n + 1]) a = (4 + s) % m, b = (n + 1 + s) % m; else if (used[m - 4] && used[n + 1]) a = (m - 4 + s) % m, b = (n + 1 + s) % m; } printf("%d %d\n", a, b); } else while (t--) { int n, m, a, b, c, d; scanf("%d%d%d%d%d", &n, &a, &b, &c, &d), m = n * 2 + 1; printf("%d\n", (m * 2 - sum(n, a, b) - sum(n, c, d)) % m); } return 0; }

match.c: In function 'main':
match.c:26:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |  scanf("%d%d", &t, &r);
      |  ^~~~~~~~~~~~~~~~~~~~~
match.c:33:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |    scanf("%d", &n), m = n * 2 + 1;
      |    ^~~~~~~~~~~~~~~
match.c:36:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     scanf("%d", &aa[i]);
      |     ^~~~~~~~~~~~~~~~~~~
match.c:71:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |    scanf("%d%d%d%d%d", &n, &a, &b, &c, &d), m = n * 2 + 1;
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~