1 #include <stdio.h> 2 #include <unistd.h> 3 recurse(int x)4int recurse(int x) { 5 if (x <= 1) 6 return 1; // recurse end 7 return recurse(x-1) + x; // recurse call 8 } 9 main(int argc,char const * argv[])10int main(int argc, char const *argv[]) { 11 recurse(20); // recurse invocation 12 return 0; 13 } 14