0_0_26542456_4410.c 0_0_26542456_4410.c(25) : error C2065: “sum1”: 未声明的标识符 0_0_26542456_4410.c(25) : error C2065: “sum2”: 未声明的标识符 0_0_26542456_4410.c(25) : error C2065: “sum3”: 未声明的标识符