排序算法

读文件读取一些正整数，算法复杂度为o(N)
利用数组下标来排序．比二分查找还快

int *a = new int [100];
        for (int i=0;i<100;++i)
                a[i] = 0;
        ifstream ift ("1.txt");
        char buf[100] = "\0";
        while(ift.good()){
                ift.getline(buf, sizeof(buf));
                if(strlen(buf)==0) continue;
                int itmp = atoi(buf);
                a[itmp] = ++a[itmp];
                cout<<"itmp="<<itmp<<" a[itmp]="<<a[itmp]<<endl;
        }
        for(int j=0;j<100;++j){
                for(;a[j]!=0;){
                        cout<<j<<endl;
                        a[j] = --a[j];
                }

        }
        delete [] a;