Compilare: user.c: In function ‘main’: user.c:26:14: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] else if(s[i]=='=') ^ user.c:6:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.in","r",stdin),freopen("ec.out","w",stdout),scanf("%d%d",&n,&m); ^ user.c:6:36: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.in","r",stdin),freopen("ec.out","w",stdout),scanf("%d%d",&n,&m); ^ user.c:6:63: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.in","r",stdin),freopen("ec.out","w",stdout),scanf("%d%d",&n,&m); ^ user.c:8:12: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a),p[a+100000]=1; ^ user.c:14:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n",s); ^