foo.c: In function 'main':
foo.c:33:9: warning: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
    if(t+abs(b[ke].j-b[i].j)+abs(b[ke].i-b[i].i)+b[i].i+3>k)
         ^~~

自豪的采用jd5进行评测(github.com/masnn/jd5)