https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=2254
这题是一道没有人通过的题。
对于这题我想到一个二分的方法，可是无论怎么调精度都通过不了。个人感觉，是精度要求的比较高，所以不容易做出这样的题。
分享一下代码：
View Code
1 /***************** Written By Lyon, From SCAU, Beta 1.4.0 **************/ 2 /**************** headers && constants && definitions ****************/ 3 #pragma comment(linker, "/STACK:102400000,102400000") 4 5 #include6 #include 7 #include 8 #include 9 #include 10 #include 11 #include 12 #include 13 #include 14 #include <string> 15 #include 16 #include 17 #include 18 #include 19 #include <set> 20 #include
UPD:
经过又一轮的调精度，代码变成这样了，数据强度也高了不少，然而还是过不了。
View Code
1 /***************** Written By Lyon, From SCAU, Beta 1.4.0 **************/ 2 /**************** headers && constants && definitions ****************/ 3 #pragma comment(linker, "/STACK:102400000,102400000") 4 5 #include6 #include 7 #include 8 #include 9 #include 10 #include 11 #include 12 #include 13 #include 14 #include <string> 15 #include 16 #include 17 #include 18 #include 19 #include <set> 20 #include
自己搞的一些测试数据：
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1 10 2 15 3 4 4 10 2 7 5 7 5 12 6 2 7 12 7 4 9 13 8 6 9 3 10 2 1 3 11 4 0 2 12 5 4 6 13 10 14 4 15 8 2 5 16 4 2 5 17 6 5 8 18 2 5 8 19 20 10000000 21 5 22 2000000 5000000 10000000 23 4000000 1 5000000 24 6000000 4999999 10000000 25 8000000 1 4999999 26 10000000 4999998 10000000 27 28 10000000 29 2 30 3 0 4 31 7499997 9999996 10000000 32 10000000 33 2 34 3 0 4 35 7499999 9999999 10000000 36 37 10000000 38 2 39 5 0 12 40 4166666 9999999 10000000 41 10000000 42 2 43 5 0 12 44 4166666 9999998 10000000 45 46 10000000 47 2 48 5 0 12 49 4166665 9999997 10000000 50 10000000 51 2 52 5 0 12 53 4166665 9999996 10000000
UPD:
View Code
1 /***************** Written By Lyon, From SCAU, Beta 1.4.0 **************/ 2 /**************** headers && constants && definitions ****************/ 3 #pragma comment(linker, "/STACK:102400000,102400000") 4 5 #include <cstdio> 6 #include <cmath> 7 #include <cstdlib> 8 #include <cstring> 9 #include <iomanip> 10 #include <iostream> 11 #include <algorithm> 12 #include <numeric> 13 #include <vector> 14 #include <string> 15 #include <bitset> 16 #include <queue> 17 #include <ctime> 18 #include <stack> 19 #include <set> 20 #include <map> 21 22 using namespace std; 23 24 #define PB push_back 25 #define FI first 26 #define SE second 27 #define MPR make_pair 28 #define REP(i, n) for (int i = 0; i < (n); i++) 29 #define REP_1(i, n) for (int i = 1; i <= (n); i++) 30 #define INC(i, a, b) for (int i = (a); i <= (b); i++) 31 #define DEC(i, a, b) for (int i = (a); i >= (b); i--) 32 #define _clr(x) memset(x, 0, sizeof(x)) 33 #define _rst(x) memset(x, -1, sizeof(x)) 34 #define SZ(x) ((int) x.size()) 35 #define PRIQ priority_queue 36 #define MSET multiset 37 #define ITOR iterator 38 #define RITOR reverse_iterator 39 #define ALL(x) x.begin(), x.end() 40 41 typedef long long LL; 42 typedef unsigned long long ULL; 43 typedef pair<int, int> PII; 44 typedef pair<double, double> PDBDB; 45 typedef pair<double, int> PDBI; 46 typedef pair<int, double> PIDB; 47 typedef vector<PIDB> VPIDB; 48 typedef vector<PDBDB> VPDBDB; 49 typedef vector<PDBI> VPDBI; 50 typedef pair<PII, int> PIII; 51 typedef pair<PII, string> PIIS; 52 typedef vector<int> VI; 53 typedef vector<LL> VL; 54 typedef vector<PII> VPII; 55 typedef vector<PIII> VPIII; 56 typedef vector<double> VDBL; 57 typedef vector<string> VSTR; 58 typedef vector<VSTR> VVSTR; 59 typedef vector<VI> VVI; 60 typedef vector<char> VCH; 61 typedef vector<VCH> VVCH; 62 typedef vector<bool> VBL; 63 typedef long double LDB; 64 65 const int N = 5e3 + 100; 66 const int M = 1 << 5; 67 const int LEN = 105; 68 const int hashMod = 1e6 + 5; 69 const int inf = 0x55555555; 70 const double eps = 1e-8; 71 const LDB leps = 1e-10; 72 const LL linf = 0x5555555555555555ll; 73 const double finf = 1e50; 74 const double pi = acos(-1.0); 75 const int mod = 1e9 + 7; 76 77 template> inline T sqr(T x) { 78 return x * x; 79 } 80 /*********************************************************************/ 81 82 struct Target { 83 LDB y, l, r; 84 Target(LDB _y = 0.0, LDB _l = 0.0, LDB _r = 0.0) { 85 y = _y, l = _l, r = _r; 86 if (l > r) swap(l, r); 87 } 88 } ; 89 vector<Target> rec; 90 91 bool cmp(Target a, Target b) { 92 return a.y < b.y; 93 } 94 95 int test(LDB x) { 96 LDB L = (rec[0].l - x - eps) / rec[0].y, R = (rec[0].r - x + eps) / rec[0].y; 97 REP_1(i, SZ(rec) - 1) { 98 LDB tmpL = (rec[i].l - x - eps) / rec[i].y, tmpR = (rec[i].r - x + eps) / rec[i].y; 99 if (R < tmpL) return 1; 100 if (tmpR < L) return -1; 101 L = max(tmpL, L), R = min(tmpR, R); 102 } 103 return 0; 104 } 105 106 bool bs(LDB w) { 107 LDB l = 0, r = w, m; 108 while (r - l > eps) { 109 m = (l + r) / 2.0; 110 int res = test(m); 111 if (res == 0) { 112 // cout << m << endl; 113 return true; 114 } else if (res == -1) l = m; 115 else r = m; 116 } 117 return false; 118 } 119 120 void input(int n) { 121 LDB d, l, r; 122 rec.clear(); 123 REP(i, n) { 124 cin >> d >> l >> r; 125 rec.PB(Target(d, l, r)); 126 } 127 sort(ALL(rec), cmp); 128 } 129 130 int main() { 131 // freopen("in", "r", stdin); 132 int T, n; 133 LDB w; 134 while (~scanf("%d", &T)) { 135 while (T--) { 136 cin >> w >> n; 137 input(n); 138 bs(w) ? puts("YES") : puts("NO"); 139 } 140 } 141 return 0; 142 }
上面这个代码过了更多精度要求更高的数据，可惜还是WA了。
UPD:
协助管理员把数据改正过来了，然后我的代码AC了！~~~
——written by Lyon