View Compilation Error

2_28700_2479873_7950.c
2_28700_2479873_7950.c(6) : error C2065: “bool”: 未声明的标识符
2_28700_2479873_7950.c(6) : error C2146: 语法错误: 缺少“;”(在标识符“flag”的前面)
2_28700_2479873_7950.c(6) : error C2065: “flag”: 未声明的标识符
2_28700_2479873_7950.c(13) : error C2065: “flag”: 未声明的标识符
2_28700_2479873_7950.c(13) : error C2065: “true”: 未声明的标识符
2_28700_2479873_7950.c(15) : error C2065: “flag”: 未声明的标识符
2_28700_2479873_7950.c(15) : error C2065: “false”: 未声明的标识符
2_28700_2479873_7950.c(17) : error C2065: “flag”: 未声明的标识符
2_28700_2479873_7950.c(17) : error C2065: “true”: 未声明的标识符