View Compilation Error

0_0_3243902_9381.c:2:20: iostream: No such file or directory
0_0_3243902_9381.c:3:17: stack: No such file or directory
0_0_3243902_9381.c:4: error: syntax error before "namespace"
0_0_3243902_9381.c: In function `main':
0_0_3243902_9381.c:25: error: `stack' undeclared (first use in this function)
0_0_3243902_9381.c:25: error: (Each undeclared identifier is reported only once
0_0_3243902_9381.c:25: error: for each function it appears in.)
0_0_3243902_9381.c:25: error: syntax error before "float"
0_0_3243902_9381.c:26: error: syntax error before "char"
0_0_3243902_9381.c:27: error: `opnd' undeclared (first use in this function)
0_0_3243902_9381.c:28: error: `optr' undeclared (first use in this function)