C++ 差分数组

/*
差分数组：快速实现区间增减 
*/          0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
	a[11]={ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
	s[11]={ 0,-1, 1, 3, 4, 1, 1,-2, 1, 1, 1};
	a[11]={ 0,-1, 0, 3, 7, 8, 9, 7, 8, 9, 10};
[a,b] +x  s[a]+=x  s[b+1]-=x
	
	s[i]=a[i]-a[i-1]
	a[i]=a[i-1]+s[i]
[1,5] -2  { 0,-1, 0, 1, 2, 3, 6, 7, 8, 9, 10};  
          { 0,-1, 1, 1, 1, 1, 3, 1, 1, 1, 1};
[4,6] +3  { 0,-1, 0, 1, 5, 6, 9, 7, 8, 9, 10}; 
[3,5] +2  { 0,-1, 0, 3, 7, 8, 9, 7, 8, 9, 10};