在本地用scanf测试前两个测试点没有问题，但一提交就全wa。换cin就可以过。

#include <iostream>
#include <cstdio>
using namespace std;
char c;
int t[800005];
bool a[200005], lazy[800005];
int n, m, op, x, y;
void build(int q, int l, int r){
	if(l == r){
		t[q] = a[l];
		return;
	}
	int mid = (l + r) >> 1;
	build(q * 2, l, mid);
	build(q * 2 + 1, mid + 1, r);
	t[q] = t[q * 2] + t[q * 2 + 1];
}
void push_down(int q, int l, int r){
	if(lazy[q]){
		lazy[q] = false;
		lazy[q * 2] = !lazy[q * 2];
		lazy[q * 2 + 1] = !lazy[q * 2 + 1];
		int mid = (l + r) >> 1;
		t[q * 2] = (mid - l + 1) - t[q * 2];
		t[q * 2 + 1] = (r - mid) - t[q * 2 + 1];
		t[q] = t[q * 2] + t[q * 2 + 1];
	}
}
void update(int q, int l, int r, int x, int y){
	if(x <= l && y >= r){
		t[q] = (r - l + 1) - t[q];
		lazy[q] = !lazy[q];
		return;
	}
	int mid = (l + r) >> 1;
	push_down(q, l, r);
	if(y <= mid){
		update(q * 2, l, mid, x, y);
	}
	else if(x > mid){
		update(q * 2 + 1, mid + 1, r, x, y);
	}
	else{
		update(q * 2, l, mid, x, y);
		update(q * 2 + 1, mid + 1, r, x, y);
	}
	t[q] = t[q * 2] + t[q * 2 + 1];
}
int getsum(int q, int l, int r, int x, int y){
	if(x <= l && y >= r){
		return t[q];
	}
	int mid = (l + r) >> 1;
	push_down(q, l, r);
	if(y <= mid){
		return getsum(q * 2, l, mid, x, y);
	}
	else if(x > mid){
		return getsum(q * 2 + 1, mid + 1, r, x, y);
	}
	else{
		return (getsum(q * 2 + 1, mid + 1, r, x, y) + getsum(q * 2, l, mid, x, y));
	}
}
int main(){
	scanf("%d%d", &n, &m);
	scanf("%c", &c);
	for(int i = 1; i <= n; i++){
		scanf("%c", &c);
		a[i] = c - '0';
	}
	build(1, 1, n);
	while(m--){
		scanf("%d%d%d", &op, &x, &y);
		if(op == 0){
			update(1, 1, n, x, y);
		}
		else{
			printf("%d\n", getsum(1, 1, n, x, y));
		}
	}
	return 0;
}