C++ 如何重复利用一个内存地址块

 1 #include<iostream>
 2 using namespace std;
 3 const int size = 10;
 4 double buf[size] = {0};
 5
 6 int main(int argv ,char * args[]) {
 7
 8     double *p1,*p2;
 9      p1 = new double[size];
10      p2 = new (buf)double[size];
11      for (int i = 0; i < size; i++) {
12          p1[i]=p2[(i+2)%size]=i+2;
13          cout << "p1== " << &p1[i] << "    p1[i]=="<<p1[i]<<"   "<< endl;
14      }
15      cout << "---------------华丽丽的分割线-----------------------" << endl;
16      for (int i = 0; i < size; i++) {
17          cout << "p2== " << &p2[i] << "    p2[i]==" << p2[i] << "   " << endl;
18      }
19      cout << "---------------一大波内存袭来！-----------------------" << endl;
20      double *p3, *p4;
21      p3 = new double[size];
22      p4 = new (buf)double[size];
23      for (int i = 0; i < size; i++) {
24          p3[i] = p4[(i + 2) % size] = i + 2;
25          cout << "p3== " << &p3[i] << "    p3[i]==" << p3[i] << "   " << endl;
26      }
27      cout << "---------------华丽丽的分割线-----------------------" << endl;
28      for (int i = 0; i < size; i++) {
29          cout << "p4== " << &p4[i] << "    p4[i]==" << p4[i] << "   " << endl;
30      }
31      cout << "###################华丽丽的分割线########################" << endl;
32      //数组指针
33      double *p[] = {p1,p2,p3,p4};
34      for (int i = 0; i < 4; i++)
35          for (int j = 0; j < size; j++) {
36              cout << "p["<<i<<"]== " << &p[i][j] << "    p["<<i<<"]"<<"["<<j<<"]==" << p[i][j] << "   " << endl;
37          }
38
39      for (int i = 0; i < 4; i++) {
40           //释放new创建的内存
41          if (p[i]!=buf)  delete [] p[i] ;
42      }
43      cout << "内存释放之后" << endl;
44      for (int i = 0; i < size; i++) {
45
46          cout << "p1== " << &p1[i] << "    p1[i]==" << p1[i] << "   " << endl;
47      }
48      cin.get();
49     return 0;
50 }

 1 p1== 0038DC28    p1[i]==2
 2 p1== 0038DC30    p1[i]==3
 3 p1== 0038DC38    p1[i]==4
 4 p1== 0038DC40    p1[i]==5
 5 p1== 0038DC48    p1[i]==6
 6 p1== 0038DC50    p1[i]==7
 7 p1== 0038DC58    p1[i]==8
 8 p1== 0038DC60    p1[i]==9
 9 p1== 0038DC68    p1[i]==10
10 p1== 0038DC70    p1[i]==11
11 ---------------华丽丽的分割线-----------------------
12 p2== 0125C2D0    p2[i]==10
13 p2== 0125C2D8    p2[i]==11
14 p2== 0125C2E0    p2[i]==2
15 p2== 0125C2E8    p2[i]==3
16 p2== 0125C2F0    p2[i]==4
17 p2== 0125C2F8    p2[i]==5
18 p2== 0125C300    p2[i]==6
19 p2== 0125C308    p2[i]==7
20 p2== 0125C310    p2[i]==8
21 p2== 0125C318    p2[i]==9
22 ---------------一大波内存袭来！-----------------------
23 p3== 0038B1F8    p3[i]==2
24 p3== 0038B200    p3[i]==3
25 p3== 0038B208    p3[i]==4
26 p3== 0038B210    p3[i]==5
27 p3== 0038B218    p3[i]==6
28 p3== 0038B220    p3[i]==7
29 p3== 0038B228    p3[i]==8
30 p3== 0038B230    p3[i]==9
31 p3== 0038B238    p3[i]==10
32 p3== 0038B240    p3[i]==11
33 ---------------华丽丽的分割线-----------------------
34 p4== 0125C2D0    p4[i]==10
35 p4== 0125C2D8    p4[i]==11
36 p4== 0125C2E0    p4[i]==2
37 p4== 0125C2E8    p4[i]==3
38 p4== 0125C2F0    p4[i]==4
39 p4== 0125C2F8    p4[i]==5
40 p4== 0125C300    p4[i]==6
41 p4== 0125C308    p4[i]==7
42 p4== 0125C310    p4[i]==8
43 p4== 0125C318    p4[i]==9
44 ###################华丽丽的分割线########################
45 p[0]== 0038DC28    p[0][0]==2
46 p[0]== 0038DC30    p[0][1]==3
47 p[0]== 0038DC38    p[0][2]==4
48 p[0]== 0038DC40    p[0][3]==5
49 p[0]== 0038DC48    p[0][4]==6
50 p[0]== 0038DC50    p[0][5]==7
51 p[0]== 0038DC58    p[0][6]==8
52 p[0]== 0038DC60    p[0][7]==9
53 p[0]== 0038DC68    p[0][8]==10
54 p[0]== 0038DC70    p[0][9]==11
55 p[1]== 0125C2D0    p[1][0]==10
56 p[1]== 0125C2D8    p[1][1]==11
57 p[1]== 0125C2E0    p[1][2]==2
58 p[1]== 0125C2E8    p[1][3]==3
59 p[1]== 0125C2F0    p[1][4]==4
60 p[1]== 0125C2F8    p[1][5]==5
61 p[1]== 0125C300    p[1][6]==6
62 p[1]== 0125C308    p[1][7]==7
63 p[1]== 0125C310    p[1][8]==8
64 p[1]== 0125C318    p[1][9]==9
65 p[2]== 0038B1F8    p[2][0]==2
66 p[2]== 0038B200    p[2][1]==3
67 p[2]== 0038B208    p[2][2]==4
68 p[2]== 0038B210    p[2][3]==5
69 p[2]== 0038B218    p[2][4]==6
70 p[2]== 0038B220    p[2][5]==7
71 p[2]== 0038B228    p[2][6]==8
72 p[2]== 0038B230    p[2][7]==9
73 p[2]== 0038B238    p[2][8]==10
74 p[2]== 0038B240    p[2][9]==11
75 p[3]== 0125C2D0    p[3][0]==10
76 p[3]== 0125C2D8    p[3][1]==11
77 p[3]== 0125C2E0    p[3][2]==2
78 p[3]== 0125C2E8    p[3][3]==3
79 p[3]== 0125C2F0    p[3][4]==4
80 p[3]== 0125C2F8    p[3][5]==5
81 p[3]== 0125C300    p[3][6]==6
82 p[3]== 0125C308    p[3][7]==7
83 p[3]== 0125C310    p[3][8]==8
84 p[3]== 0125C318    p[3][9]==9
85 内存释放之后
86 p1== 0038DC28    p1[i]==-1.45682e+144
87 p1== 0038DC30    p1[i]==-1.45682e+144
88 p1== 0038DC38    p1[i]==-1.45682e+144
89 p1== 0038DC40    p1[i]==-1.45682e+144
90 p1== 0038DC48    p1[i]==-1.45682e+144
91 p1== 0038DC50    p1[i]==-1.45682e+144
92 p1== 0038DC58    p1[i]==-1.45682e+144
93 p1== 0038DC60    p1[i]==-1.45682e+144
94 p1== 0038DC68    p1[i]==-1.45682e+144
95 p1== 0038DC70    p1[i]==-1.45682e+144   

这样，可以对内存进行很好的利用，避免内存泄露。而导致系统运行越来越慢！