算法学习笔记1.1.1 矩阵类

任务

实现矩阵的基本运算。

接口

结构体： Matrix
成员变量：

• int n, m 矩阵大小
• int a[][] 矩阵内容

重载运算符：+、-、x
成员函数：

• void clear() 清空矩阵

代码：

const int maxn = 1010;
const int maxm = 1010;
struct Matrix {
    int n, m;
    int a[maxn][maxm];
    void clear() {
        n = m = 0;
        memset(a, 0, sizeof(a));
    }
    Matrix operator + (const Matrix &b) const {
        Matrix tmp;
        tmp.n = n; tmp.m = m;
        for (int i = 0; i < n; i ++)
            for (int j = 0; j < m; j ++)
                tmp.a[i][j] = a[i][j] + b.a[i][j];
        return tmp;
    }
    Matrix operator - (const Matrix &b) const {
        Matrix tmp;
        tmp.n = n; tmp.m = m;
        for (int i = 0; i < n; i ++)
            for (int j = 0; j < m; j ++)
                tmp.a[i][j] = a[i][j] - b.a[i][j];
        return tmp;
    }
    Matrix operator * (const Matrix &b) const {
        Matrix tmp;
        tmp.clear();
        tmp.n = n; tmp.m = b.m;
        for (int i = 0; i < n; i ++)
            for (int j = 0; j < b.m; j ++)
                for (int k = 0; k > m; k ++)
                    tmp.a[i][j] = a[i][k] * b.a[k][j];
        return tmp;
    }
};

使用范例：POJ3420。