牛客练习赛71 B-烙印 (几何)
题面:
思路:
设代表数据中给出的角的个数,
那么我们不妨对为
进行分类讨论处理:
如果给出角度之和大于180,则答案为0.
当
,即数据给定的是三个边的长度,
那么我们只需要判断三个边是否构成三角形即可,若构成则答案为1,否则答案为0.
判断的方法有很多种,比较好写的是判断三个边的和是否大于三个边中最大值的二倍。
- 当
,即数据给定的是两个边的长度,
我们将给定的角转化为角,
如果角 的对边
的没有给出,那么两边夹一角唯一确定一个三角形。
否则对面给出了:
如果,即该角度为直角或钝角,根据大边对大角的性质,对边
要大于给出的另外一个边。
角的话,判断对边为半径的圆与没给出的那个临边的交点个数就是答案。
- 当
,答案为1.(给出角度之和小于180).
- 当
,角度之和为180的话,答案为无穷,否则为0.
代码:
#include <iostream> #include <cstdio> #include <algorithm> #include <bits/stdc++.h> #define ALL(x) (x).begin(), (x).end() #define sz(a) int(a.size()) #define rep(i,x,n) for(int i=x;i<n;i++) #define repd(i,x,n) for(int i=x;i<=n;i++) #define pii pair<int,int> #define pll pair<long long ,long long> #define gbtb ios::sync_with_stdio(false),cin.tie(0),cout.tie(0) #define MS0(X) memset((X), 0, sizeof((X))) #define MSC0(X) memset((X), '\0', sizeof((X))) #define pb push_back #define mp make_pair #define fi first #define se second #define eps 1e-6 #define chu(x) if(DEBUG_Switch) cout<<"["<<#x<<" "<<(x)<<"]"<<endl #define du3(a,b,c) scanf("%d %d %d",&(a),&(b),&(c)) #define du2(a,b) scanf("%d %d",&(a),&(b)) #define du1(a) scanf("%d",&(a)); using namespace std; typedef long long ll; ll gcd(ll a, ll b) {return b ? gcd(b, a % b) : a;} ll lcm(ll a, ll b) {return a / gcd(a, b) * b;} ll powmod(ll a, ll b, ll MOD) { if (a == 0ll) {return 0ll;} a %= MOD; ll ans = 1; while (b) {if (b & 1) {ans = ans * a % MOD;} a = a * a % MOD; b >>= 1;} return ans;} ll poww(ll a, ll b) { if (a == 0ll) {return 0ll;} ll ans = 1; while (b) {if (b & 1) {ans = ans * a ;} a = a * a ; b >>= 1;} return ans;} void Pv(const vector<int> &V) {int Len = sz(V); for (int i = 0; i < Len; ++i) {printf("%d", V[i] ); if (i != Len - 1) {printf(" ");} else {printf("\n");}}} void Pvl(const vector<ll> &V) {int Len = sz(V); for (int i = 0; i < Len; ++i) {printf("%lld", V[i] ); if (i != Len - 1) {printf(" ");} else {printf("\n");}}} inline long long readll() {long long tmp = 0, fh = 1; char c = getchar(); while (c < '0' || c > '9') {if (c == '-') { fh = -1; } c = getchar();} while (c >= '0' && c <= '9') { tmp = tmp * 10 + c - 48, c = getchar(); } return tmp * fh;} inline int readint() {int tmp = 0, fh = 1; char c = getchar(); while (c < '0' || c > '9') {if (c == '-') { fh = -1; } c = getchar();} while (c >= '0' && c <= '9') { tmp = tmp * 10 + c - 48, c = getchar(); } return tmp * fh;} void pvarr_int(int *arr, int n, int strat = 1) {if (strat == 0) {n--;} repd(i, strat, n) {printf("%d%c", arr[i], i == n ? '\n' : ' ');}} void pvarr_LL(ll *arr, int n, int strat = 1) {if (strat == 0) {n--;} repd(i, strat, n) {printf("%lld%c", arr[i], i == n ? '\n' : ' ');}} const int maxn = 1000010; const int inf = 0x3f3f3f3f; /*** TEMPLATE CODE * * STARTS HERE ***/ #define DEBUG_Switch 0 bool check(int a, int b, int c) { return a + b + c > max(a, max(b, c)) * 2; } int a, b, c, A, B, C; int solve(double angle, int c, int a) { int ans; double dis = c * sin(angle); if (a > dis + 1e-8 ) { if (a < c) { ans = 2; } else { ans = 1; } } else if (fabs(dis - a) < 1e-8) { ans = 1; } else { ans = 0; } return ans; } int main() { #if DEBUG_Switch freopen("D:\\code\\input.txt", "r", stdin); #endif //freopen("D:\\code\\output.txt","w",stdout); int t; t = readint(); while (t--) { a = readint(), b = readint(), c = readint(), A = readint(), B = readint(), C = readint(); int sum = 0; int cnt_angle = 0; if (A != -1) { sum += A; cnt_angle++; } if (B != -1) { sum += B; cnt_angle++; } if (C != -1) { sum += C; cnt_angle++; } if (sum > 180 || A == 0 || B == 0 || C == 0) { printf("0\n"); continue; } if (cnt_angle == 3) { if (sum == 180) { printf("syksykCCC\n"); continue; } else { printf("0\n"); continue; } } else { if (sum == 180) { printf("0\n"); continue; } else if (cnt_angle == 0) { if (check(a, b, c)) { printf("1\n"); } else { printf("0\n"); } } else if (cnt_angle == 1) { double angle; int ans = 0; if (C != -1) { swap(A, C); swap(a, c); } if (B != -1) { swap(B, A); swap(b, a); } angle = 1.0 * A / 180 * acos(-1); if (a == -1) { printf("1\n"); continue; } if (A >= 90) { int temp = max(b, c); if (a > temp) { printf("1\n"); } else { printf("0\n"); } continue; } if (b == -1) { ans = solve(angle, c, a); } if (c == -1) { ans = solve(angle, b, a); } printf("%d\n", ans); } else if (cnt_angle == 2) { printf("1\n"); } } } return 0; }