Compilare: user.c: In function ‘main’: user.c:9:1: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(matrix, -1, 1001*1001*sizeof(int)); ^ user.c:9:1: warning: incompatible implicit declaration of built-in function ‘memset’ [enabled by default] user.c:14:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &N); ^ user.c:17:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &P1[i]); ^ user.c:21:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &P2[i]); ^