/in/foo.c: In function 'main':
/in/foo.c:8:5: warning: implicit declaration of function 'scanf_s' [-Wimplicit-function-declaration]
     scanf_s("%s", &str,100);
     ^~~~~~~
/in/foo.c:16:41: error: 'bigNum' undeclared (first use in this function)
     printf("大写字符个数：%d\n", bigNum);
                                         ^~~~~~
/in/foo.c:16:41: note: each undeclared identifier is reported only once for each function it appears in