1.多项式为0，直接输出0
2.系数为0的项不输出
3.注意double类型的判0
1 #include <iostream> 2 #include <vector> 3 #include <iomanip> 4 #include <cmath> 5 using namespace std; 6 7 int main() 8 { 9 vector<int> a, b;//次数 10 vector<double>a1, b1;//系数 11 vector<int>sum;//次数 12 vector<double>sum1;//系数 13 int Ka; 14 int fz = 1;//多项式为0标志，fz==0时不为0 15 cin >> Ka; 16 for (int i = 0; i < Ka; i++) 17 { 18 int temp; 19 double temp2; 20 cin >> temp; 21 a.push_back(temp); 22 cin >> temp2; 23 a1.push_back(temp2); 24 } 25 int Kb; 26 cin >> Kb; 27 for (int i = 0; i < Kb; i++) 28 { 29 int temp; 30 double temp2; 31 cin >> temp; 32 b.push_back(temp); 33 cin >> temp2; 34 b1.push_back(temp2); 35 for (int j = 0; j < Ka; j++) 36 { 37 if (a[j] == b[i]) 38 { 39 b1[i] += a1[j]; 40 } 41 } 42 } 43 int K = Ka > Kb ? Ka : Kb; 44 int i, j; 45 for (i = 0, j = 0; i < Ka || j < Kb;) 46 { 47 if (i < Ka && j < Kb) 48 { 49 if (a[i] == b[j])//a，b有同次项时先把a系数加到b系数上 50 { 51 if (fabs(b1[j]) > 1e-15) 52 { 53 fz = 0; 54 sum.push_back(b[j]); 55 sum1.push_back(b1[j]); 56 } 57 i++; 58 j++; 59 } 60 else if (a[i] != b[j]) 61 { 62 if (a[i] > b[j]) 63 { 64 if (fabs(a1[i]) > 1e-15) 65 { 66 fz = 0; 67 sum.push_back(a[i]); 68 sum1.push_back(a1[i]); 69 } 70 i++; 71 } 72 else 73 { 74 if (fabs(b1[j]) > 1e-15) 75 { 76 fz = 0; 77 sum.push_back(b[j]); 78 sum1.push_back(b1[j]); 79 } 80 j++; 81 } 82 } 83 } 84 else if (i == Ka) 85 { 86 if (fabs(b1[j]) > 1e-15) 87 { 88 fz = 0; 89 sum.push_back(b[j]); 90 sum1.push_back(b1[j]); 91 } 92 j++; 93 } 94 else if (j == Kb) 95 { 96 if (fabs(a1[i]) > 1e-15) 97 { 98 fz = 0; 99 sum.push_back(a[i]); 100 sum1.push_back(a1[i]); 101 } 102 i++; 103 } 104 } 105 int flag_out = 0;//标记是否第一次输出，控制输出格式 106 if (fz == 1)cout << "0"; 107 else 108 { 109 cout << sum.size() << ' '; 110 for (int i = 0; i < sum.size(); i++) 111 { 112 if (flag_out == 0) 113 { 114 cout << setprecision(1) << fixed << sum[i] << ' ' << sum1[i]; 115 flag_out = 1; 116 } 117 else 118 { 119 cout << setprecision(1) << fixed << ' ' << sum[i] << ' ' << sum1[i]; 120 } 121 } 122 } 123 return 0; 124 }