Suppose the input data is an array, and input[m] stores m numbers.

int exist[n]= { 0 }； //Indicates whether the number in 1-n appears.

int I = 0；

for(I = 0； I & ltm；; i++) {

int number = input[I]；

There exists [number-1] = 1

}

If a number a appears, then exist[a- 1] is 1, otherwise it is 0.

Sum to get the result.

The second problem is linear programming. You didn't give the photo.