c++實現單純形法現行規劃問題的求解(推薦)
阿新 • • 發佈:2020-04-03
在本程式中預設該現行規劃問題有最優解
針對此問題:
#include<iostream> using namespace std; int check(float *sigema,int m) { for (int i = 1; i <= m ; i++) { if (sigema[i] > 0) { return 0; } } return 1; } //此程式已經化為標準型的線性規劃問題中,且預設有最優解 int main(int argc,char* argv[]) { //資料輸入部分 int m,n; cout << "請輸入變數個數:"; cin >> m; cout << "請輸入不等式個數:"; cin >> n; float **matrix = new float*[n + 1]; //係數矩陣 for (int i = 1; i <= n; i++) { matrix[i] = new float[m + 2]; } float *cj = new float[m + 1]; float *cB = new float[n + 1]; //基變數係數 int *XB = new int[n + 1]; //用來標註基變數x的下標 float *b = new float[n + 1]; float *sigema = new float[n + 1]; float *sita = new float[n + 1]; //初始化 for (int i = 0; i <= m; i++) { cj[i] = 0; } for (int i = 0; i <= n; i++) { cB[i] = 0; XB[i] = 0; b[i] = 0; sigema[i] = 0; sita[i] = 0; } cout << "請輸入目標函式係數(用空格間開):" << endl; for (int i = 1; i <= m; i++) { cin >> cj[i]; } cout << "請輸入各不等式的係數和常量(用空格間開):" << endl; for (int i = 1; i <= n; i++) { cout << "不等式" << i << ": "; for (int j = 1; j <= m + 1; j++) { cin >> matrix[i][j]; } } cout << "請輸入目標函式中基變數下標:" << endl; for (int i = 1; i <= n; i++) { cin >> XB[i]; cB[i] = cj[XB[i]]; //常量 b[i] = matrix[i][m + 1]; } //計算檢驗數 for (int i = 1; i <= m; i++) { sigema[i] = cj[i]; for (int j = 1; j <= n; j++) { sigema[i] -= cB[j] * matrix[j][i]; } } while (check(sigema,m) == 0) { //尋找入基變數 float maxn = sigema[1]; int sigema_xindex = 0; float sigema_xcoefficient = 0; for (int i = 1; i <= m; i++) { if (maxn <= sigema[i]) { maxn = sigema[i]; sigema_xindex = i; sigema_xcoefficient = cj[i]; } } //計算sita for (int i = 1; i <= n; i++) { if (matrix[i][sigema_xindex] > 0) { sita[i] = b[i] / matrix[i][sigema_xindex]; } else { sita[i] = 9999; //表示sita值為負數 } } //尋找出基變數 float minn = sita[1]; int sita_xindex = 0; for (int i = 1; i <= n; i++) { if (minn >= sita[i] && sita[i] > 0) { minn = sita[i]; sita_xindex = i; } } //入基出基變換,先入基再出基 //入基操作 for (int i = 1; i <= n; i++) { if (i == sita_xindex) { XB[i] = sigema_xindex; cB[i] = sigema_xcoefficient; break; } } //出基計算 //化1 //cout << endl << "此處為化1的結果------" << endl; float mul1 = matrix[sita_xindex][sigema_xindex]; for (int i = 1; i <= m; i++) { matrix[sita_xindex][i] /= mul1; } b[sita_xindex] /= mul1; //化0 //cout << endl << "此處為化0的結果------" << endl; for (int i = 1; i <= n; i++) { if (i == sita_xindex) { continue; } float mul2 = matrix[i][sigema_xindex] / matrix[sita_xindex][sigema_xindex]; for (int j = 1; j <= m; j++) { matrix[i][j] -= (matrix[sita_xindex][j] * mul2); } b[i] -= (b[sita_xindex] * mul2); } for (int i = 1; i <= n; i++) { if (i == sita_xindex) { continue; } } for (int i = 1; i <= m; i++) { sigema[i] = cj[i]; for (int j = 1; j <= n; j++) { sigema[i] -= cB[j] * matrix[j][i]; } } } float MaxZ = 0; float *result = new float[m + 1]; for (int i = 0; i <= m; i++) { result[i] = 0; } for (int i = 1; i <= n; i++) { result[XB[i]] = b[i]; } cout << "最優解為:X = ("; for (int i = 1; i < m; i++) { cout << result[i] << ","; } cout << result[m] << ")" << endl; for (int i = 1; i <= m; i++) { MaxZ += result[i] * cj[i]; } cout << "最優值為:MzxZ = " << MaxZ; return 0; }
程式執行結果:
總結
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