foo.cc: In function 'int main()':
foo.cc:12:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d%d",&n,&m,&p,&q);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

自豪的采用 HydroJudge 进行评测(github.com/hydro-dev/HydroJudge)

您没有提供题目配置文件。正在使用默认时空限制 1s 256M 。
识别到10个测试点
{"receive":"2020-07-25T01:03:51.535Z","handle":"2020-07-25T01:03:51.535Z","cache_start":"2020-07-25T01:03:51.549Z","read_cases":"2020-07-25T01:03:51.670Z","judge":"2020-07-25T01:03:51.670Z","done":"2020-07-25T01:03:53.216Z"}