Problem 13

#include<cstdlib>
#include<cstdio>
#include<cstring>
int map[3][100005];
int main()
{
    int n,q,s=0,r,c,f;
    memset(map,0,sizeof(map));
    scanf("%d %d",&n,&q);
    map[1][1]=2;
    map[2][n]=2;
    while(q--)
    {
        scanf("%d %d",&r,&c);
        f=(r==1?2:1);
        if(map[r][c])
        {
            if(c>1&&map[f][c-1]==1)
                s--;
            if(map[f][c]==1)
                s--;
            if(c<n&&map[f][c+1]==1)
                s--;
        }
        else
        {
            if(c>1&&map[f][c-1]==1)
                s++;
            if(map[f][c]==1)
                s++;
            if(c<n&&map[f][c+1]==1)
                s++;
        }
        map[r][c]=!map[r][c];
        if(s)
            printf("No\n");
        else
            printf("Yes\n");
    }
    return 0;
}