这样可以，程序呢？呵呵！

没测算，不知结果对否。
#include <stdio.h>
main()
{
    int m[7]={7,6,5,4,3,2,1};
    int n[7]={22,6,5,4,3,2,1};
    char a[7]={0};
    int i,j, mc, nc;
    char sm[256], sn[256];
    for (i=0; i<7; i++)
    {
        for (j=1; j<=i; j++)
            a[j] = 1;
        while (1)
        {
            mc = m[0];
            nc = n[0];
            sprintf(sm, "%s", "m0");
            sprintf(sn, "%s", "n0");
            for (j=1; j<=i; j++)
            {
                if (a[j])
                {
                    mc += m[j];
                    nc += n[j];
                    sprintf(sm, "%s+m%d", sm,j);
                    sprintf(sn, "%s+n%d", sn,j);
                }
                else
                {
                    mc -= m[j];
                    nc -= n[j];
                    sprintf(sm, "%s-m%d", sm,j);
                    sprintf(sn, "%s-n%d", sn,j);
                }
            }
            printf("%s/%s = ", sm,sn);
            printf("%lf\n", (double)mc/nc);
            for (j=i; j>0; j--)
            {
                if (a[j])
                {
                    a[j] = 0;
                    break;
                }
            }
            if (j == 0)
                break;
            for (++j; j<=i; j++)
                a[j] = 1;   
        }
        printf("\n===============================\n");
    }
}

感谢指教！应该是正确的，程序很有逻辑；条件限制很多，我自己的水平是写不出来的；

m0/n0 = 0.318182

===============================
m0+m1/n0+n1 = 0.464286
m0-m1/n0-n1 = 0.062500

===============================
m0+m1+m2/n0+n1+n2 = 0.545455
m0+m1-m2/n0+n1-n2 = 0.347826
m0-m1+m2/n0-n1+n2 = 0.285714
m0-m1-m2/n0-n1-n2 = -0.363636

===============================
m0+m1+m2+m3/n0+n1+n2+n3 = 0.594595
m0+m1+m2-m3/n0+n1+n2-n3 = 0.482759
m0+m1-m2+m3/n0+n1-n2+n3 = 0.444444
m0+m1-m2-m3/n0+n1-n2-n3 = 0.210526
m0-m1+m2+m3/n0-n1+n2+n3 = 0.400000
m0-m1+m2-m3/n0-n1+n2-n3 = 0.117647
m0-m1-m2+m3/n0-n1-n2+n3 = 0.000000
m0-m1-m2-m3/n0-n1-n2-n3 = -1.142857

===============================
m0+m1+m2+m3+m4/n0+n1+n2+n3+n4 = 0.625000
m0+m1+m2+m3-m4/n0+n1+n2+n3-n4 = 0.558824
m0+m1+m2-m3+m4/n0+n1+n2-n3+n4 = 0.531250
m0+m1+m2-m3-m4/n0+n1+n2-n3-n4 = 0.423077
m0+m1-m2+m3+m4/n0+n1-n2+n3+n4 = 0.500000
m0+m1-m2+m3-m4/n0+n1-n2+n3-n4 = 0.375000
m0+m1-m2-m3+m4/n0+n1-n2-n3+n4 = 0.318182
m0+m1-m2-m3-m4/n0+n1-n2-n3-n4 = 0.062500
m0-m1+m2+m3+m4/n0-n1+n2+n3+n4 = 0.464286
m0-m1+m2+m3-m4/n0-n1+n2+n3-n4 = 0.318182
m0-m1+m2-m3+m4/n0-n1+n2-n3+n4 = 0.250000
m0-m1+m2-m3-m4/n0-n1+n2-n3-n4 = -0.071429
m0-m1-m2+m3+m4/n0-n1-n2+n3+n4 = 0.166667
m0-m1-m2+m3-m4/n0-n1-n2+n3-n4 = -0.250000
m0-m1-m2-m3+m4/n0-n1-n2-n3+n4 = -0.500000
m0-m1-m2-m3-m4/n0-n1-n2-n3-n4 = -2.750000

===============================
m0+m1+m2+m3+m4+m5/n0+n1+n2+n3+n4+n5 = 0.642857
m0+m1+m2+m3+m4-m5/n0+n1+n2+n3+n4-n5 = 0.605263
m0+m1+m2+m3-m4+m5/n0+n1+n2+n3-n4+n5 = 0.583333
m0+m1+m2+m3-m4-m5/n0+n1+n2+n3-n4-n5 = 0.531250
m0+m1+m2-m3+m4+m5/n0+n1+n2-n3+n4+n5 = 0.558824
m0+m1+m2-m3+m4-m5/n0+n1+n2-n3+n4-n5 = 0.500000
m0+m1+m2-m3-m4+m5/n0+n1+n2-n3-n4+n5 = 0.464286
m0+m1+m2-m3-m4-m5/n0+n1+n2-n3-n4-n5 = 0.375000
m0+m1-m2+m3+m4+m5/n0+n1-n2+n3+n4+n5 = 0.531250
m0+m1-m2+m3+m4-m5/n0+n1-n2+n3+n4-n5 = 0.464286
m0+m1-m2+m3-m4+m5/n0+n1-n2+n3-n4+n5 = 0.423077
m0+m1-m2+m3-m4-m5/n0+n1-n2+n3-n4-n5 = 0.318182
m0+m1-m2-m3+m4+m5/n0+n1-n2-n3+n4+n5 = 0.375000
m0+m1-m2-m3+m4-m5/n0+n1-n2-n3+n4-n5 = 0.250000
m0+m1-m2-m3-m4+m5/n0+n1-n2-n3-n4+n5 = 0.166667
m0+m1-m2-m3-m4-m5/n0+n1-n2-n3-n4-n5 = -0.071429
m0-m1+m2+m3+m4+m5/n0-n1+n2+n3+n4+n5 = 0.500000
m0-m1+m2+m3+m4-m5/n0-n1+n2+n3+n4-n5 = 0.423077
m0-m1+m2+m3-m4+m5/n0-n1+n2+n3-n4+n5 = 0.375000
m0-m1+m2+m3-m4-m5/n0-n1+n2+n3-n4-n5 = 0.250000
m0-m1+m2-m3+m4+m5/n0-n1+n2-n3+n4+n5 = 0.318182
m0-m1+m2-m3+m4-m5/n0-n1+n2-n3+n4-n5 = 0.166667
m0-m1+m2-m3-m4+m5/n0-n1+n2-n3-n4+n5 = 0.062500
m0-m1+m2-m3-m4-m5/n0-n1+n2-n3-n4-n5 = -0.250000
m0-m1-m2+m3+m4+m5/n0-n1-n2+n3+n4+n5 = 0.250000
m0-m1-m2+m3+m4-m5/n0-n1-n2+n3+n4-n5 = 0.062500
m0-m1-m2+m3-m4+m5/n0-n1-n2+n3-n4+n5 = -0.071429
m0-m1-m2+m3-m4-m5/n0-n1-n2+n3-n4-n5 = -0.500000
m0-m1-m2-m3+m4+m5/n0-n1-n2-n3+n4+n5 = -0.250000
m0-m1-m2-m3+m4-m5/n0-n1-n2-n3+n4-n5 = -0.875000
m0-m1-m2-m3-m4+m5/n0-n1-n2-n3-n4+n5 = -1.500000
m0-m1-m2-m3-m4-m5/n0-n1-n2-n3-n4-n5 = -6.500000

===============================
m0+m1+m2+m3+m4+m5+m6/n0+n1+n2+n3+n4+n5+n6 = 0.651163
m0+m1+m2+m3+m4+m5-m6/n0+n1+n2+n3+n4+n5-n6 = 0.634146
m0+m1+m2+m3+m4-m5+m6/n0+n1+n2+n3+n4-n5+n6 = 0.615385
m0+m1+m2+m3+m4-m5-m6/n0+n1+n2+n3+n4-n5-n6 = 0.594595
m0+m1+m2+m3-m4+m5+m6/n0+n1+n2+n3-n4+n5+n6 = 0.594595
m0+m1+m2+m3-m4+m5-m6/n0+n1+n2+n3-n4+n5-n6 = 0.571429
m0+m1+m2+m3-m4-m5+m6/n0+n1+n2+n3-n4-n5+n6 = 0.545455
m0+m1+m2+m3-m4-m5-m6/n0+n1+n2+n3-n4-n5-n6 = 0.516129
m0+m1+m2-m3+m4+m5+m6/n0+n1+n2-n3+n4+n5+n6 = 0.571429
m0+m1+m2-m3+m4+m5-m6/n0+n1+n2-n3+n4+n5-n6 = 0.545455
m0+m1+m2-m3+m4-m5+m6/n0+n1+n2-n3+n4-n5+n6 = 0.516129
m0+m1+m2-m3+m4-m5-m6/n0+n1+n2-n3+n4-n5-n6 = 0.482759
m0+m1+m2-m3-m4+m5+m6/n0+n1+n2-n3-n4+n5+n6 = 0.482759
m0+m1+m2-m3-m4+m5-m6/n0+n1+n2-n3-n4+n5-n6 = 0.444444
m0+m1+m2-m3-m4-m5+m6/n0+n1+n2-n3-n4-n5+n6 = 0.400000
m0+m1+m2-m3-m4-m5-m6/n0+n1+n2-n3-n4-n5-n6 = 0.347826
m0+m1-m2+m3+m4+m5+m6/n0+n1-n2+n3+n4+n5+n6 = 0.545455
m0+m1-m2+m3+m4+m5-m6/n0+n1-n2+n3+n4+n5-n6 = 0.516129
m0+m1-m2+m3+m4-m5+m6/n0+n1-n2+n3+n4-n5+n6 = 0.482759
m0+m1-m2+m3+m4-m5-m6/n0+n1-n2+n3+n4-n5-n6 = 0.444444
m0+m1-m2+m3-m4+m5+m6/n0+n1-n2+n3-n4+n5+n6 = 0.444444
m0+m1-m2+m3-m4+m5-m6/n0+n1-n2+n3-n4+n5-n6 = 0.400000
m0+m1-m2+m3-m4-m5+m6/n0+n1-n2+n3-n4-n5+n6 = 0.347826
m0+m1-m2+m3-m4-m5-m6/n0+n1-n2+n3-n4-n5-n6 = 0.285714
m0+m1-m2-m3+m4+m5+m6/n0+n1-n2-n3+n4+n5+n6 = 0.400000
m0+m1-m2-m3+m4+m5-m6/n0+n1-n2-n3+n4+n5-n6 = 0.347826
m0+m1-m2-m3+m4-m5+m6/n0+n1-n2-n3+n4-n5+n6 = 0.285714
m0+m1-m2-m3+m4-m5-m6/n0+n1-n2-n3+n4-n5-n6 = 0.210526
m0+m1-m2-m3-m4+m5+m6/n0+n1-n2-n3-n4+n5+n6 = 0.210526
m0+m1-m2-m3-m4+m5-m6/n0+n1-n2-n3-n4+n5-n6 = 0.117647
m0+m1-m2-m3-m4-m5+m6/n0+n1-n2-n3-n4-n5+n6 = 0.000000
m0+m1-m2-m3-m4-m5-m6/n0+n1-n2-n3-n4-n5-n6 = -0.153846
m0-m1+m2+m3+m4+m5+m6/n0-n1+n2+n3+n4+n5+n6 = 0.516129
m0-m1+m2+m3+m4+m5-m6/n0-n1+n2+n3+n4+n5-n6 = 0.482759
m0-m1+m2+m3+m4-m5+m6/n0-n1+n2+n3+n4-n5+n6 = 0.444444
m0-m1+m2+m3+m4-m5-m6/n0-n1+n2+n3+n4-n5-n6 = 0.400000
m0-m1+m2+m3-m4+m5+m6/n0-n1+n2+n3-n4+n5+n6 = 0.400000
m0-m1+m2+m3-m4+m5-m6/n0-n1+n2+n3-n4+n5-n6 = 0.347826
m0-m1+m2+m3-m4-m5+m6/n0-n1+n2+n3-n4-n5+n6 = 0.285714
m0-m1+m2+m3-m4-m5-m6/n0-n1+n2+n3-n4-n5-n6 = 0.210526
m0-m1+m2-m3+m4+m5+m6/n0-n1+n2-n3+n4+n5+n6 = 0.347826
m0-m1+m2-m3+m4+m5-m6/n0-n1+n2-n3+n4+n5-n6 = 0.285714
m0-m1+m2-m3+m4-m5+m6/n0-n1+n2-n3+n4-n5+n6 = 0.210526
m0-m1+m2-m3+m4-m5-m6/n0-n1+n2-n3+n4-n5-n6 = 0.117647
m0-m1+m2-m3-m4+m5+m6/n0-n1+n2-n3-n4+n5+n6 = 0.117647
m0-m1+m2-m3-m4+m5-m6/n0-n1+n2-n3-n4+n5-n6 = 0.000000
m0-m1+m2-m3-m4-m5+m6/n0-n1+n2-n3-n4-n5+n6 = -0.153846
m0-m1+m2-m3-m4-m5-m6/n0-n1+n2-n3-n4-n5-n6 = -0.363636
m0-m1-m2+m3+m4+m5+m6/n0-n1-n2+n3+n4+n5+n6 = 0.285714
m0-m1-m2+m3+m4+m5-m6/n0-n1-n2+n3+n4+n5-n6 = 0.210526
m0-m1-m2+m3+m4-m5+m6/n0-n1-n2+n3+n4-n5+n6 = 0.117647
m0-m1-m2+m3+m4-m5-m6/n0-n1-n2+n3+n4-n5-n6 = 0.000000
m0-m1-m2+m3-m4+m5+m6/n0-n1-n2+n3-n4+n5+n6 = 0.000000
m0-m1-m2+m3-m4+m5-m6/n0-n1-n2+n3-n4+n5-n6 = -0.153846
m0-m1-m2+m3-m4-m5+m6/n0-n1-n2+n3-n4-n5+n6 = -0.363636
m0-m1-m2+m3-m4-m5-m6/n0-n1-n2+n3-n4-n5-n6 = -0.666667
m0-m1-m2-m3+m4+m5+m6/n0-n1-n2-n3+n4+n5+n6 = -0.153846
m0-m1-m2-m3+m4+m5-m6/n0-n1-n2-n3+n4+n5-n6 = -0.363636
m0-m1-m2-m3+m4-m5+m6/n0-n1-n2-n3+n4-n5+n6 = -0.666667
m0-m1-m2-m3+m4-m5-m6/n0-n1-n2-n3+n4-n5-n6 = -1.142857
m0-m1-m2-m3-m4+m5+m6/n0-n1-n2-n3-n4+n5+n6 = -1.142857
m0-m1-m2-m3-m4+m5-m6/n0-n1-n2-n3-n4+n5-n6 = -2.000000
m0-m1-m2-m3-m4-m5+m6/n0-n1-n2-n3-n4-n5+n6 = -4.000000
m0-m1-m2-m3-m4-m5-m6/n0-n1-n2-n3-n4-n5-n6 = -14.000000

===============================
Press any key to continue

看上去像加减的排列组合问题~

很好的数学算法；实际工作里遇到的问题，有解了；


#include <stdio.h>
main()
{
    int m[7]={7,6,5,4,3,2,1};
    int n[7]={22,6,5,4,3,2,1};
    char a[7]={0};
    int i,j, mc, nc;
   
    for (i=0; i<7; i++)
    {
        for (j=1; j<=i; j++)
            a[j] = 1;
        while (1)
        {
            mc = m[0];
            nc = n[0];
            
            for (j=1; j<=i; j++)
            {
                if (a[j])
                {
                    mc += m[j];
                    nc += n[j];
                    
                }
                else
                {
                    mc -= m[j];
                    nc -= n[j];
                  
                }
            }
        
            printf("%lf\n", (double)mc/nc);
            for (j=i; j>0; j--)
            {
                if (a[j])
                {
                    a[j] = 0;
                    break;
                }
            }
            if (j == 0)
                break;
            for (++j; j<=i; j++)
                a[j] = 1;   
        }
        printf("\n===============================\n");
    }
}


0.318182

===============================
0.464286
0.062500

===============================
0.545455
0.347826
0.285714
-0.363636

===============================
0.594595
0.482759
0.444444
0.210526
0.400000
0.117647
0.000000
-1.142857

===============================
0.625000
0.558824
0.531250
0.423077
0.500000
0.375000
0.318182
0.062500
0.464286
0.318182
0.250000
-0.071429
0.166667
-0.250000
-0.500000
-2.750000

===============================
0.642857
0.605263
0.583333
0.531250
0.558824
0.500000
0.464286
0.375000
0.531250
0.464286
0.423077
0.318182
0.375000
0.250000
0.166667
-0.071429
0.500000
0.423077
0.375000
0.250000
0.318182
0.166667
0.062500
-0.250000
0.250000
0.062500
-0.071429
-0.500000
-0.250000
-0.875000
-1.500000
-6.500000

===============================
0.651163
0.634146
0.615385
0.594595
0.594595
0.571429
0.545455
0.516129
0.571429
0.545455
0.516129
0.482759
0.482759
0.444444
0.400000
0.347826
0.545455
0.516129
0.482759
0.444444
0.444444
0.400000
0.347826
0.285714
0.400000
0.347826
0.285714
0.210526
0.210526
0.117647
0.000000
-0.153846
0.516129
0.482759
0.444444
0.400000
0.400000
0.347826
0.285714
0.210526
0.347826
0.285714
0.210526
0.117647
0.117647
0.000000
-0.153846
-0.363636
0.285714
0.210526
0.117647
0.000000
0.000000
-0.153846
-0.363636
-0.666667
-0.153846
-0.363636
-0.666667
-1.142857
-1.142857
-2.000000
-4.000000
-14.000000

===============================
Press any key to continue