1009 Edge Detection

#include <iostream.h> 
#include <math.h> 
typedef int RLE[2]; 
int w,n,ct,t; 
RLE r[2000]; 
RLE cur,pos; 
bool Move(RLE a, RLE b, int offset) { 
    if ( a[0]<0 || a[0]>=n ) return false; 
    b[0] = a[0]; b[1] = a[1]+offset; 
    while ( b[1]>=r[b[0]][1] && b[0]<n ) { 
        b[1] -= r[b[0]][1]; 
        b[0]++; 
    } 
    if ( b[0]>=n ) return false; 
    while ( b[1]<0 && b[0]>=0 ) { 
        b[0]--; 
        b[1] += r[b[0]][1]; 
    } 
    if ( b[0]<0 ) return false; 
    return true; 
} 
void Advance() { 
    int temp = r[pos[0]][1]-pos[1]-w-1; 
    if ( pos[1]>w && temp>0 ) { 
        cur[1] += temp; 
        ct += temp; 
        pos[1] += temp; 
    } 
    temp = w-2 - ct%w; 
    int temp2 = r[pos[0]][1]-pos[1]-2; 
    if ( pos[1]==0 || pos[1]==1 || ct%w==0 ) temp2 = 0; 
    int temp3,temp4; 
    RLE trle; 
    if ( !Move(pos, trle, -w-2) ) temp3 = w; 
    else temp3 = r[trle[0]][1]-trle[1]-3; 
    if ( !Move(pos, trle, w-2) ) temp4 = w; 
    else temp4 = r[trle[0]][1]-trle[1]-3; 
    temp = (temp<temp2)?temp:temp2; 
    temp = (temp<temp3)?temp:temp3; 
    temp = (temp<temp4)?temp:temp4; 
    if ( temp>0 ) { 
        cur[1] += temp; 
        ct += temp; 
        pos[1] += temp; 
    } 
    int hehe=0; 
    Move(pos, trle, -w-1); 
    if ( ct>=w && ct%w>0 ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    Move(pos, trle, -w); 
    if ( ct>=w ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    Move(pos, trle, -w+1); 
    if ( ct>=w && ct%w!=w-1 ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    Move(pos, trle, -1); 
    if ( ct%w>0 ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    Move(pos, trle, 1); 
    if ( ct%w!=w-1 ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    Move(pos, trle, w-1); 
    if ( ct<t-w && ct%w>0 ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    Move(pos, trle, w); 
    if ( ct<t-w ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    Move(pos, trle, w+1); 
    if ( ct<t-w && ct%w!=w-1 ) { 
        temp = abs(r[trle[0]][0] - r[pos[0]][0]); 
        if ( temp>hehe ) hehe = temp; 
    } 
    if ( cur[0] == -1 ) { 
        cur[0] = hehe; 
        cur[1] = 1; 
    } else if ( hehe == cur[0] ) cur[1]++; 
    else { 
        cout<<cur[0]<<' '<<cur[1]<<endl; 
        cur[0] = hehe; 
        cur[1] = 1; 
    } 
    pos[1]++; ct++; 
    if ( pos[1] == r[pos[0]][1] ) {pos[0]++; pos[1]=0;} 
} 
void Output() { 
    cur[0] = -1; cur[1] = -1; 
    pos[0] = 0; pos[1] = 0; 
    while ( true ) { 
        if ( pos[0] == n ) break; 
        Advance(); 
    } 
    cout<<cur[0]<<' '<<cur[1]<<endl; 
} 
int main() 
{ 
    cin>>w; 
    while ( w>0 ) { 
        cout<<w<<endl; 
        n=0; 
        cin>>r[n][0]>>r[n][1]; 
        t=r[n][1];ct=0; 
        while ( r[n][1]>0 ) { 
            n++; 
            cin>>r[n][0]>>r[n][1]; 
            t += r[n][1]; 
        } 
        Output(); 
        cout<<"0 0"<<endl; 
        cin>>w; 
    } 
    cout<<w<<endl; 

    return 0; 
} 

评论

2 楼 z_q 2011-03-02  

问一下大牛，advance中第一个 cur[1] += temp; 是三行都填充一样的值因而可以累加，那temp2,temp3,temp4是记录什么？

1 楼 z_q 2011-03-01  

楼主的代码优化太厉害了，不知道其中涉及到-2的表达式语句是什么意思？