0_0_19725663_17138.cpp: In function 'int main()': 0_0_19725663_17138.cpp:16:20: error: 'strlen' was not declared in this scope int n1 = strlen(a); ^ 0_0_19725663_17138.cpp:77:19: error: 'strlen' was not declared in this scope int n1 = strlen(a); ^