为什么我在本地测这道题的样例时它不输出，但洛谷一交就过了？

#include<iostream>
#include<cstdio>
#include<cmath>
#include<string>
#include<cstring>
#include<algorithm>
#include<bits/stdc++.h>
//#pragma G++ optimize(2)
//#pragma G++ optimize(3, "Ofast", "inline")
using namespace std;
char s[1000005], ss;
string t;
int n, a, tt, len;
bool b = true;
int main() {
	scanf("%s", s);
	len = strlen(s);
	scanf("%d\n", &n);
	for(int i = 1;i <= n;i++){
		cin >> t;
		if(t == "<"){
			scanf("%d", &tt);
			if(b){
				a += tt;
			}else{
				a -= tt;
			}
		}else if(t == ">"){
			scanf("%d", &tt);
			if(b){
				a -= tt;
			}else{
				a += tt;
			}
		}else{
			b = !b;
			do{
				scanf("%c", &ss);
			}while(ss != '\n');
		}
		while(a < 0){
			a += len;
		}
		while(a >= len){
			a -= len;
		}
	}
	if(b){
		for(int i = a;i < len;i++){
			printf("%c", s[i]);
		}
		for(int i = 0;i < a;i++){
			printf("%c", s[i]);
		}
	}else{//a-1 -> 0 -> a
		for(int i = a - 1;i >= 0;i--){
			printf("%c", s[i]);
		}
		for(int i = len - 1;i >= a;i--){
			printf("%c", s[i]);
		}
	}
	return 0;
}