题解 | #剩下的树#

#include <stdio.h>

void Remian_tree(int Tree[],int start,int end){
    for(int i=start;i<=end;i++){
        Tree[i]=0;
    }
}

int main() {
    int Tree[10001],count=0;
    int sum_tree,qujian,start,end;
    scanf("%d %d",&sum_tree,&qujian);
    for(int i=1;i<=sum_tree+1;i++){
        Tree[i]=1;
    }
    for(int i=0;i<qujian;i++){
        scanf("%d %d",&start,&end);
        Remian_tree(Tree, start, end);
    }
    for(int i=1;i<=sum_tree+1;i++){
        if(Tree[i]){
            count++;
        }
    }
    printf("%d",count);
    return 0;
}