AcWing 795. 前缀和[D7](12.23)

795. 前缀和 - AcWing题库

AcWing 795. 前缀和

n, m = map(int, input().split())
ls = list(map(int,input().split()))
a = [0] + ls
s = [0] * (len(ls)+1)
for i in range(1,len(a)):
    s[i] = s[i-1] +a[i]
for i in range(m):
    l, r = map(int, input().split())
    sum = s[r] - s[l-1]
    print(sum)