#include <bits/stdc++.h>
#define LL long long
using namespace std;
const int N = 1e7 + 10;
const int INF = 0x3f3f3f3f;
int n , m;
int f (int x , int y)
{
	if (x == y)
	   return 1;
    if (x == 1)
	   return y;
	if (y == 1)
	  return x;
	if (x > y)
	   return f (x - y , y) + 1;
	else return f (y - x , x) + 1;
	
	
	   
	
}
int main()
{
	    cin >> n >> m;
	    cout << f (n , m);
		return 0;
}

递归用着用着就出问题了，改用while时才发现问题，懒得改了

#include<iostream>//cin cout
#include<iomanip>//setprecision setw
#include<stdio.h>//scanf printf
#include<math.h>//ceil floor fabs sqrt round pow
#include<string>//string
#include<string.h>//memset
#include<sstream>//stringsream
#include<algorithm>//min max
using namespace std;
typedef long long ll;
int n,m,cnt;
int main(){
	cin>>n>>m;
	while(n&&m){
		if(n>m){
			cnt++;
			if(n==m)break;
			n-=m;
		}else if(n<m){
			cnt++;
			if(n==m)break;
			m-=n;
		}else {
			cnt++;
			break;
		}
	}
	cout<<cnt;
	return 0;
}