Main.cc:1:1: error: ‘include’ does not name a type; did you mean ‘__has_include’? include "string.h" ^~~~~~~ __has_include Main.cc: In function ‘void str_replace(char*, int, char*)’: Main.cc:9:16: error: ‘strlen’ was not declared in this scope lenofstr = strlen(str); ^~~~~~ Main.cc:9:16: note: suggested alternative: ‘str’ lenofstr = strlen(str); ^~~~~~ str Main.cc:33:5: error: ‘strncpy’ was not declared in this scope strncpy(cp,str,lenofstr); ^~~~~~~ Main.cc:33:5: note: suggested alternative: ‘struct’ strncpy(cp,str,lenofstr); ^~~~~~~ struct Main.cc:7:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ Main.cc: In function ‘int main()’: Main.cc:45:5: error: ‘printf’ was not declared in this scope printf("\n请输入要查找的字符串和用于替换的字符串(中间用空格隔开): "); ^~~~~~ Main.cc:45:5: note: suggested alternative: ‘int’ printf("\n请输入要查找的字符串和用于替换的字符串(中间用空格隔开): "); ^~~~~~ int Main.cc:46:5: error: ‘scanf’ was not declared in this scope scanf("%s",str2); ^~~~~ In file included from Main.cc:2:0: Main.cc:49:28: error: ‘stdin’ was not declared in this scope freopen("news.txt","r",stdin); ^ Main.cc:49:5: error: ‘freopen’ was not declared in this scope freopen("news.txt","r",stdin); ^~~~~~~ Main.cc:51:9: error: ‘getchar’ was not declared in this scope c = getchar(); ^~~~~~~ Main.cc:51:9: note: suggested alternative: ‘getc’ c = getchar(); ^~~~~~~ getc Main.cc:61:9: error: ‘strstr’ was not declared in this scope p = strstr(str1,str2); ^~~~~~ Main.cc:61:9: note: suggested alternative: ‘str3’ p = strstr(str1,str2); ^~~~~~ str3 Main.cc:66:23: error: ‘strlen’ was not declared in this scope str_replace(p,strlen(str2),str3); ^~~~~~ Main.cc:66:23: note: suggested alternative: ‘len’ str_replace(p,strlen(str2),str3); ^~~~~~ len Main.cc:41:11: warning: unused variable ‘len’ [-Wunused-variable] int i,len,count=0; ^~~