HDU 1542-Atlanta

Scanning line + line segment tree, line segment tree writing a bit degraded, casually --...

  1 /*  2 ID:esxgx1  3 LANG:C++  4 PROG:hdu1542  5 */  6 #include <cstdio>  7 #include <cstring>  8 #include <deque>  9 #include <algorithm> 10 using namespace std; 11  12 #define eps        1e-5 13 #define NN    1007 14  15 struct rt{ 16     double x, y1, y2; 17     int val; 18 }; 19 rt rr[NN << 1]; 20 double mapx[NN << 1], mapy[NN << 1]; 21  22  23 #define MAXN    (NN << 1) 24  25 int cnt[MAXN * 4]; 26 double sum[MAXN * 4]; 27  28 #define recursive_def    int l, int r, int i 29 #define lsi            i<<1 30 #define rsi            i<<1 | 1 31 #define lsn            l, m, lsi 32 #define rsn            m, r, rsi 33  34 #define pushup        sum[i] = sum[lsi] + sum[rsi]; 35  36 void build(recursive_def) 37 { 38     cnt[i] = 0; 39     sum[i] = 0; 40     if (l == r) return; 41     int m = (l+r) >> 1; 42     build(lsn); 43     if (l != m) build(rsn); 44 } 45  46 void update(int L, int R, int val, recursive_def) 47 { 48     if (l + 1 == r) { 49         if (L <= l && r <= R) { 50             if (cnt[i] * (cnt[i] + val)<=0) 51                 sum[i] += val * (mapy[r] - mapy[l]); 52             cnt[i] += val; 53 //            printf("%f %f (%f)\n", mapy[l], mapy[r], sum[i]); 54         } 55         return; 56     } 57     int m = (l+r) >> 1; 58     if (L <= m) update(L, R, val, lsn); 59     if (m <= R && l != m) update(L, R, val, rsn); 60     pushup 61 //    printf("%f %f (%f)\n", mapy[l], mapy[r], sum[i]); 62 } 63  64 int cmp1(const rt &a, const rt &b) 65 { 66     return a.x < b.x; 67 } 68  69 int main(void) 70 { 71     #ifndef ONLINE_JUDGE 72     freopen("in.txt", "r", stdin); 73     #endif 74  75     int Case = 1; 76     int n; 77     while(scanf("%d", &n), n) { 78             int ri, px, py; 79             ri = px = py = 0; 80             for(int i=0; i<n; ++i) { 81                     double x1, y1, x2, y2; 82                     scanf("%lf%lf%lf%lf", &x1, &y1, &x2, &y2); 83                     rr[ri].x = x1, rr[ri].y1 = y1, rr[ri].y2 = y2; 84                     rr[ri].val = 1; ++ri; 85                     rr[ri].x = x2, rr[ri].y1 = y1, rr[ri].y2 = y2; 86                     rr[ri].val = -1; ++ri; 87                     mapx[px++] = x1; mapx[px++] = x2; 88                     mapy[py++] = y1; mapy[py++] = y2; 89             } 90  91             sort(rr, rr + ri, cmp1); 92             sort(mapx, mapx + px); px = unique(mapx, mapx + px) - mapx; 93             sort(mapy, mapy + py); py = unique(mapy, mapy + py) - mapy; 94             int j; 95             double lx, S; 96             lx = S = 0, j = 0; 97             build(0, py - 1, 1); 98             for(int i=0; i<ri; ++i) { 99                 while ((mapx[j] - rr[i].x) <= eps) ++j;100                 S += (rr[i].x - lx) * sum[1];101 //                printf("%d %f %f\n", i, sum[1], (rr[i].x - lx) * sum[1]);102                 lx = rr[i].x;103                 int y1 = lower_bound(mapy, mapy + py, rr[i].y1) - mapy;104                 int y2 = lower_bound(mapy, mapy + py, rr[i].y2) - mapy;105 //                printf("->%d %d %d\n", y1, y2, rr[i].val);106                 update(y1, y2, rr[i].val, 0, py - 1, 1);107             }108             printf("Test case #%d\nTotal explored area: %.2f\n\n", Case, S);109             ++Case;110     }111     return 0;112 }

 

2014-07-28 17:39:31

Accepted

1542

0 ms

324 K

2503 B

G ++