一个二维向量的题

[Dreamz]

这个题是用3个函数分别实现二维数组的输入,每一行的求和以及求平均值,现在的情况是输入数据后求出的每行的和以及平均值都不对,看不出是哪里的问题,还请大家帮忙解决,谢谢先:)

#include <iostream>
#include <vector>
using namespace std;

typedef vector<int> vi;
typedef vector<vi> vii;

vii input(const int m, const int n)
{
	vii a;
	a.resize(m);
	for (int i=0; i<a.size(); ++i)
	{
		a[i].resize(n);
	}
	for (int i=0; i<a.size(); ++i)
	{
		for (int j=0; j<a[i].size(); ++j)
			cin >> a[i][j];
	}
	return a;
}

void total(vii a)
{
	int sum = 0;
	for (int i=0; i<a.size(); i++)
	{
		for (int j=0; j<a[i].size(); j++)
		{
			sum += a[i][j];
		}
		cout << i+1 << ' : ' << sum << endl;
	}
}

void average(vii a)
{
	int sum = 0;
	for (int i=0; i<a.size(); i++)
	{
		for (int j=0; j<a[i].size(); j++)
		{
			sum += a[j][i];
		}
		cout << "NO " << i << " average is " << double(sum)/2 << endl;
	}
}

int main()
{
	vii matrix = input(2,2);
	total(matrix);
	average(matrix);

	return 0;
}

[qqwx_1986]

void average(vii a)
{
    int sum = 0;
    for (int i=0; i<a.size(); i++)
    {
        for (int j=0; j<a[i].size(); j++)
        {
            sum += a[j][i];//==>sum += a[i][j];
        }
        cout << "NO " << i << " average is " << double(sum)/2 << endl;
    }
}

[Dreamz]

求平均值这里是粗心的错误,但是每一行求和那里还没看出来是哪里的问题...

[Dreamz]

自己发现错误了,字符串用' '来标记了,真晕= =

[qqwx_1986]

vii input(const int m, const int n)
{
    vii a;
    a.resize(m);
    for (int i=0; i<a.size(); ++i)
    {
        a[i].resize(n);
    }
    for (int i=0; i<a.size(); ++i)
    {
        for (int j=0; j<a[i].size(); ++j)
            cin >> a[i][j];
    }
    return a;//临时变量，生命周期随函数的结束而结束
}
建议改为
void input(const int m, const int n,vii &a)
{
    a.resize(m);
    for (int i=0; i<a.size(); ++i)
    {
        a[i].resize(n);
    }
    for (int i=0; i<a.size(); ++i)
    {
        for (int j=0; j<a[i].size(); ++j)
            cin >> a[i][j];
    }
}
...
int main()
{
    vii matrix ;
    input(2,2,matrix);
    total(matrix);
    average(matrix);

    return 0;
}

[Qkill]

#include <iostream>
#include <vector>
using namespace std;

typedef vector<int> vi;
typedef vector<vi> vii;



void input(vii &a, const int m, const int n)
{
// vii a;
a.resize(m);
for (int i=0; i<a.size(); ++i)
{
a[i].resize(n);
}
for (i=0; i<a.size(); ++i)
{
for (int j=0; j<a[i].size(); ++j)
cin >> a[i][j];
}
// return a;
}

void total(vii a)
{
int sum = 0;
for (int i=0; i<a.size(); i++)
{
for (int j=0; j<a[i].size(); j++)
{
sum += a[i][j];
}
cout << i+1 << ':' << sum << endl;
sum = 0;
}
}

void average(vii a)
{
int sum = 0;
for (int i=0; i<a.size(); i++)
{
for (int j=0; j<a[i].size(); j++)
{
sum += a[i][j];
}
cout << "NO " << i << " average is " << (double)sum/2 << endl;
sum = 0;
}
}

int main()
{
vii matrix;
input(matrix, 2, 2);
total(matrix);
average(matrix);

return 0;
}

[Dreamz]

谢谢球球,刚看到你的最新回复,呵呵