hdu 4331 Image Recognition

wa的有点无语，细节比较多的题对我来说真伤不起。。。

#include<iostream>#include<vector>#include<string>#include<cstdio>#include<iomanip>#include<algorithm>using namespace std;#define pb push_back#define read            freopen("out.txt","r",stdin)  #define write           freopen("zz.txt","w",stdout)  const int maxn = 1005;struct zz{int now;bool w;}zx;vector<zz>g[maxn];int a[maxn][maxn];int u[maxn][maxn];int d[maxn][maxn];int r[maxn][maxn];int l[maxn][maxn];int x[maxn][maxn];int fd[maxn];int n;int lowbit(int x){return x&(-x);}void insert(int x){while(x<maxn){fd[x]++;x+=lowbit(x);}return ;}int find(int x){int temp = x - 1;int re=0;while(temp>0){re+=fd[temp];temp-=lowbit(temp);}return re;}int start(){int temp;int now;int tot;for(int k=2;k<=2*n;k++){tot = 0;for(int i=0;i<=n;i++){g[i].clear();}for(int i=1;i<=n;i++){if(k-i<1 || k-i>n) continue;if(!a[i][k-i]) continue;temp = i-min(u[i][k-i],r[i][k-i]);zx.now = i;zx.w = false;g[temp].pb(zx);zx.w = true;temp = i;g[temp].pb(zx);}memset(fd,0,sizeof(fd));for(int i=1;i<=n;i++){if(k-i<1 || k-i>n) continue;if(a[i][k-i]) {temp = i+min(l[i][k-i],d[i][k-i])-1;insert(temp);tot++;}for(int j=0;j<g[i].size();j++){if(g[i][j].w){now = g[i][j].now;x[now][k-now]+=tot-find(now);}else{now = g[i][j].now;x[now][k-now]-=tot-find(now);}}}}int ans=0;for(int i=1;i<=n;i++){for(int j=1;j<=n;j++){ans+=x[i][j];}}return ans;}int main(){    int T;    cin>>T;    for(int tt=1;tt<=T;tt++)    {        cin>>n;        for(int i=1;i<=n;i++) for(int j=1;j<=n;j++){scanf("%d",&a[i][j]);x[i][j]=u[i][j]=d[i][j]=r[i][j]=l[i][j]=0;}for(int i=1;i<=n;i++) for(int j=1;j<=n;j++)if(a[i][j]) {u[i][j]=u[i-1][j]+1;}for(int i=n;i>=1;i--) for(int j=1;j<=n;j++) if(a[i][j]){d[i][j]=d[i+1][j]+1;}for(int i=1;i<=n;i++) for(int j=1;j<=n;j++)if(a[i][j]){l[i][j]=l[i][j-1]+1;}for(int i=1;i<=n;i++) for(int j=n;j>=1;j--) if(a[i][j]) {r[i][j]=r[i][j+1]+1;     }cout<<"Case "<<tt<<": "<<start()<<endl;    }    return 0;}