Compilare: main.c: In function 'main': main.c:26:20: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] else if(s[i]=='=') ^ main.c:7:2: 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); ^~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:7:29: 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); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:7:58: 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); ^~~~~~~~~~~~~~~~~~~ main.c:9:7: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a),p[a+100000]=1; ^~~~~~~~~~~~~~ main.c:15:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n",s); ^~~~~~~~~~~~~~~