0_0_7981977_12321.c:1:19: iostream: No such file or directory 0_0_7981977_12321.c:2:17: cstdio: No such file or directory 0_0_7981977_12321.c:3:20: algorithm: No such file or directory 0_0_7981977_12321.c:5: error: syntax error before "namespace"