View Compilation Error

0_0_13978490_8985.c:5:1: error: unknown type name 'bool'
 bool b[501];
 ^
0_0_13978490_8985.c: In function 'main':
0_0_13978490_8985.c:14:18: error: 'false' undeclared (first use in this function)
         memset(b,false,sizeof(b));
                  ^
0_0_13978490_8985.c:14:18: note: each undeclared identifier is reported only once for each function it appears in
0_0_13978490_8985.c:36:18: error: 'true' undeclared (first use in this function)
             b[t]=true;
                  ^