母函数，先要算搞清楚组合数可能的最大值。非常大。N种设备的最大VAL*最大数量。

1 #include 
     
       2 #include 
      
        3  4 #define MAXNUM 500000 5  6 typedef struct { 7     int val, num; 8 } fac_st; 9 10 fac_st facs[55];11 int c1[MAXNUM], c2[MAXNUM];12 13 int main() {14     int n, sum, tmp;15     int i, j, k;16 17     while (scanf("%d", &n) != EOF && (n>=0)) {18         sum = 0;19         for (i=1; i<=n; ++i) {20             scanf("%d %d", &facs[i].val, &facs[i].num);21             sum += facs[i].val * facs[i].num;22         }23         memset(c1, 0, sizeof(c1));24         memset(c2, 0, sizeof(c2));25         for (i=0, j=0; i<=facs[1].num; ++i, j+=facs[1].val)26             c1[j] = 1;27         for (i=2; i<=n; ++i) {28             for (j=0; j<=sum; ++j) {29                 tmp = facs[i].val * facs[i].num;30                 for (k=0; k<=tmp && (k+j)<=sum; k+=facs[i].val)31                     c2[k+j] += c1[j];32             }33             for (j=0; j<=sum; ++j) {34                 c1[j] = c2[j];35                 c2[j] = 0;36             }37         }38         k = sum/2;39         if (c1[k])40             printf("%d %d\n", sum-k, k);41         else {42             for (i=k+1; i<=sum; ++i)43                 if (c1[i]) {44                     printf("%d %d\n", i, sum-i);45                     break;46                 }47         }48     }49 50     return 0;51 }