3 C:\Users\13392\Desktop\test\丈量土地.cpp multiple definition of `test1()'

This error message indicates that there are multiple definitions of the function "test1()" in your code. This can happen if you have accidentally defined the same function multiple times in different files, or if you have included the same file containing the function definition multiple times.

To fix this error, you need to remove the duplicate definitions of the "test1()" function from your code. You can do this by carefully examining all the files that include the function definition and ensuring that there is only one definition of the function. Alternatively, you can rename the function in one of the files to avoid the naming conflict.