n個(gè)點(diǎn)有三維坐標(biāo)，沒兩點(diǎn)之間有一條邊，花費(fèi)為兩點(diǎn)之間的高度差，獲利為兩點(diǎn)之間水平直線距離。最小化 花費(fèi)和 / 獲利和
01分?jǐn)?shù)規(guī)劃問(wèn)題，最優(yōu)比率生成樹模型，最大化或最小化
但是講道理上界應(yīng)該老老實(shí)實(shí)設(shè)為 1000W 對(duì)不對(duì)？因?yàn)楸荣惒皇撬㈩}
否則這組數(shù)據(jù)
input:20 0 01 0 100000000output:10000000肯定WA嘛
1:二分法1822MS
/// by ztx/// blog.csdn.net/hzoi_ztx//#include <bits/stdc++.h>// minimize sumcost / sumdistance// minimize sumvalue / sumcost// value:cost// cost:distance#define Rep(i,l,r) for(i=(l);i<=(r);i++)#define rep(i,l,r) for(i=(l);i< (r);i++)#define Rev(i,r,l) for(i=(r);i>=(l);i--)#define rev(i,r,l) for(i=(r);i> (l);i--)#define Each(i,v) for(i=v.begin();i!=v.end();i++)#define r(x) read(x)typedef long long ll ;typedef double lf ;int CH , NEG ;template <typename TP>inline void read(TP& ret) { ret = NEG = 0 ; while (CH=getchar() , CH<'!') ; if (CH == '-') NEG = true , CH = getchar() ; while (ret = ret*10+CH-'0' , CH=getchar() , CH>'!') ; if (NEG) ret = -ret ;}#define maxn 1010LL#define infi 100000000LL#define eps 1E-8F#define sqr(x) ((x)*(x))template <typename TP>inline bool MA(TP&a,const TP&b) { return a < b ? a = b, true : false; }template <typename TP>inline bool MI(TP&a,const TP&b) { return a > b ? a = b, true : false; }int n;int x[maxn], y[maxn], h[maxn];lf v[maxn][maxn], c[maxn][maxn];bool vis[maxn];lf w[maxn];inline lf PRim(lf M) { int i, j, k; lf minf, minw; memset(vis,0,sizeof vis); Rep (i,2,n) w[i] = v[1][i]-M*c[1][i]; vis[1] = true, minf = 0; rep (i,1,n) { minw = infi; Rep (j,1,n) if (!vis[j] && w[j]<minw) minw = w[j], k = j; minf += minw, vis[k] = true; Rep (j,1,n) if (!vis[j]) MI(w[j],v[k][j]-M*c[k][j]); } return minf;}int main() { int i, j; lf L, M, R; lf maxv, maxc, minv, minc; while (scanf("%d", &n)!=EOF && n) { Rep (i,1,n) scanf("%d%d%d", &x[i], &y[i], &h[i]); maxv = maxc = -infi, minv = minc = infi; rep (i,1,n) Rep (j,i+1,n) { c[i][j] = c[j][i] = sqrt(sqr((lf)x[i]-x[j])+sqr((lf)y[i]-y[j])); v[i][j] = v[j][i] = abs((lf)h[i]-h[j]); MA(maxv,v[i][j]), MI(minv,v[i][j]); MA(maxc,c[i][j]), MI(minc,c[i][j]); } L = minv/maxc, R = maxv/minc; while (R-L > 1E-6) { // L:minf>0 R:minf<=0 M = (L+R)/2.0; if (prim(M) > eps) L = M; else R = M; } printf("%.3f/n", R); } END: getchar(), getchar(); return 0;}2:Dinkelbach算法235MS
/// by ztx/// blog.csdn.net/hzoi_ztx//#include <bits/stdc++.h>// minimize sumcost / sumdistance// minimize sumvalue / sumcost// value:cost// cost:distance/* "http:///"表示改動(dòng)過(guò)的地方 */#define Rep(i,l,r) for(i=(l);i<=(r);i++)#define rep(i,l,r) for(i=(l);i< (r);i++)#define Rev(i,r,l) for(i=(r);i>=(l);i--)#define rev(i,r,l) for(i=(r);i> (l);i--)#define Each(i,v) for(i=v.begin();i!=v.end();i++)#define r(x) read(x)typedef long long ll ;typedef double lf ;int CH , NEG ;template <typename TP>inline void read(TP& ret) { ret = NEG = 0 ; while (CH=getchar() , CH<'!') ; if (CH == '-') NEG = true , CH = getchar() ; while (ret = ret*10+CH-'0' , CH=getchar() , CH>'!') ; if (NEG) ret = -ret ;}#define maxn 1010LL#define infi 100000000LL#define eps 1E-8F#define sqr(x) ((x)*(x))template <typename TP>inline bool MA(TP&a,const TP&b) { return a < b ? a = b, true : false; }template <typename TP>inline bool MI(TP&a,const TP&b) { return a > b ? a = b, true : false; }int n;int x[maxn], y[maxn], h[maxn];lf v[maxn][maxn], c[maxn][maxn];bool vis[maxn];lf w[maxn];lf rv[maxn];///inline lf prim(lf M) { int i, j, k; lf minf, minw;lf sumc = 0, sumv = 0;/// memset(vis,0,sizeof vis); Rep (i,2,n) w[i] = v[1][i]-M*c[1][i],rv[i] = v[1][i];/// vis[1] = true, minf = 0; rep (i,1,n) { minw = infi; Rep (j,1,n) if (!vis[j] && w[j]<minw) minw = w[j], k = j;sumv += rv[k], sumc += rv[k]-w[k];/// minf += minw, vis[k] = true; Rep (j,1,n) if (!vis[j]) if (MI(w[j],v[k][j]-M*c[k][j]))rv[j] = v[k][j];/// }return sumv*M/sumc;/// return minf;}int main() { int i, j; lf L, M, R; lf maxv, maxc, minv, minc; while (scanf("%d", &n)!=EOF && n) { Rep (i,1,n) scanf("%d%d%d", &x[i], &y[i], &h[i]); maxv = maxc = -infi, minv = minc = infi; rep (i,1,n) Rep (j,i+1,n) { c[i][j] = c[j][i] = sqrt(sqr((lf)x[i]-x[j])+sqr((lf)y[i]-y[j])); v[i][j] = v[j][i] = abs((lf)h[i]-h[j]); MA(maxv,v[i][j]), MI(minv,v[i][j]); MA(maxc,c[i][j]), MI(minc,c[i][j]); } L = minv/maxc, R = maxv/minc;while (true) {/// R = prim(L);/// if (fabs(L-R) < eps) break;/// L = R;///}/// /*while (R-L > 1E-6) { // L:minf>0 R:minf<=0 M = (L+R)/2.0; if (prim(M) > eps) L = M; else R = M; }*/ printf("%.3f/n", R); } END: getchar(), getchar(); return 0;}新聞熱點(diǎn)
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