#include "stdio.h"
int fib(int n){
if(n==1 || n==2)
return n-1;
return fib(n-1)+fib(n-2);
}
int main(int argc,char *argv[]){
int sum,n,m;
printf("Please enter m & n(int 0 if(scanf("%d%d",&m,&n)!=2 || m<1 || n<1 || n<=m){
printf("Input error, exit...\n");
return 0;
}
for(sum=0;m<=n;sum+=fib(m++));
printf("The result is %d\n",sum);
return 0;
}
运行样例：
