Prefix and a two-dimensional differential +
递推式（预处理部分）：
s[i][j]=s[i-1][j]+s[i][j-1]+s[i][j]-s[i-1][j-1];
查询指定区间和：
点（x,y）到点（i,j）的区间和：s[i][j]-s[x][j]-s[i][y]+s[x][y]# Prefix and two-dimensional differential +
Guess you like
Origin www.cnblogs.com/sstealer/p/11125694.html
Recommended
Ranking