#include <stdio.h> #include <stdlib.h> int compare(const void *a, const void *b) { return (*(int*)a - *(int*)b); } int count_islands(int N, int *H, int threshold) { int islands = 0; int in_island = 0; for (int i = 0; i < N; i++) { if (H[i] >= threshold) { if (!in_island) { islands++; in_island = 1; } } else { in_island = 0; } } return islands; } int gw(int N, int *H) { if (N == 0) return 0; // Create array of unique altitudes int *unique = (int*)malloc(N * sizeof(int)); for (int i = 0; i < N; i++) { unique[i] = H[i]; } // Sort to find unique values qsort(unique, N, sizeof(int), compare); // Count unique values int unique_count = 0; for (int i = 0; i < N; i++) { if (i == 0 || unique[i] != unique[i-1]) { unique[unique_count++] = unique[i]; } } int max_islands = 0; // Try sea level just below each unique altitude for (int i = 0; i < unique_count; i++) { int islands = count_islands(N, H, unique[i]); if (islands > max_islands) { max_islands = islands; } } // Also try sea level at 0 (everything above water) int islands = count_islands(N, H, 0); if (islands > max_islands) { max_islands = islands; } free(unique); return max_islands; } int main() { int N; scanf("%d", &N); int *H = (int*)malloc(N * sizeof(int)); for (int i = 0; i < N; i++) { scanf("%d", &H[i]); } int result = gw(N, H); printf("%d\n", result); free(H); return 0; }

gw.c: In function 'main':
gw.c:68:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |     scanf("%d", &N);
      |     ^~~~~~~~~~~~~~~
gw.c:72:9: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |         scanf("%d", &H[i]);
      |         ^~~~~~~~~~~~~~~~~~