HDU & color the ball

N balloons are arranged in a row, numbered 1, 2, 3... from left to right .... n. given two integers a B (A <= B) each time, Lele colors each balloon one time from balloon a to balloon B, riding his "little pigeon" electric car. But after N times, Lele has forgotten how many times the I-th balloon has been painted. Can you help him figure out how many times each balloon has been painted?

#include <cstdlib>#include <iostream>#include<algorithm>#include<cstdio>#include<string.h>#include<string>using namespace std;int num[100006];int lowbit(int x){  return x&(-x);}void updata(int n,int k){     while(n<=100005)     {        num[n]+=k;        n+=lowbit(n);     }}int sum(int n){    int res=0;    while(n)    {       res+=num[n];       n-=lowbit(n);    }      return res;  }int main(){           int t;      while(~scanf("%d",&t)&&t)      {        memset(num,0,sizeof(num));            int x,y;        for(int i=1;i<=t;i++)           {            scanf("%d%d",&x,&y);                    updata(x,1);updata(y+1,-1);           }           printf("%d ",num[1]);           for(int i=2;i<t;i++)                      printf("%d ",sum(i));              printf("%d\n",sum(t));            //  printf("\n");      }       //system("PAUSE");    return 0;}

The key to this question is how many times I was operated by updata (x, 1), updata (Y + 1,-1), sum (I) when the array is changed; look for more groups of data to simulate

The following code has the same effect:

#include <iostream> #include<cstdio> #include<string.h> using namespace std;int f[100010]; int main() {    int n;    int i;    while ( scanf("%d",&n) , n ) {        memset(f,0,(n+1)*sizeof(int));        for ( i = 0 ; i < n ; ++i ) {            int a,b;            scanf("%d%d",&a,&b);            ++f[a];            --f[b+1];        }        int m = 0;        for (  i = 1 ; i < n ; ++i ) {            m += f[i];            printf("%d ",m);        }        m += f[i];        printf("%d\n",m);    }    return 0;}