/in/foo.c: In function 'main':
/in/foo.c:18:15: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    if (a >= 11&&a-b>=2||b>=11&&b-a>=2) //如果有人率先到达11分并且分差大于等于2，结束比赛。
               ^
/in/foo.c:34:15: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if (a >= 21 && a - b >= 2 || b >= 21 && b - a >= 2)
               ^
/in/foo.c:9:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%c", &term); 
   ^