/tmp/cciDrvPx.o: In function `dfs':

tmperbgnjjg.c:(.text+0x39c): undefined reference to `sqrt'

tmperbgnjjg.c:(.text+0x44e): undefined reference to `sqrt'

collect2: error: ld returned 1 exit status

C程序已经include 了math.h但是还是提示我没有sqrt这个函数。